Lawrence talks to me in an office at the headquarters of that ongoing battle – the Stephen Lawrence Centre in Deptford, south-east London – where she works tirelessly on the isues of social justice that prove her son’s death at least made a difference. On Monday, the anniversary of his murder, she will be attending a service in his memory at St Martin-in-the-Fields in central London. When she talks about him, though, it still tends to be in the present tense. “Stephen is always smiling like that,” she will say to me, or “That is how Stephen is”. She does it because he still feels very much part of life, she says. “There isn’t a day when I don’t talk about him in one way or the other. And now I have my three grandchildren to remind me. Ethan, my daughter’s son, is only two, but he is so similar to Stephen – he has exactly the same look in his eye.”

Sometimes she imagines how Stephen would have been now, at 38, had he lived. “I think he would have had a family, I think he would have travelled widely,” she says. “I know he would have qualified as an architect. As I often say to people: you don’t know what the future holds. Up until Stephen died, I think I took my kids, my family, for granted, like we all do. I don’t do that now.”

Lawrence lives on her own now, having separated from husband Neville in 1999. She spends most days here in the office. Part of the work of her foundation is to give young people the opportunities that Stephen was so brutally denied. She has raised the money for aspiring architects who would otherwise struggle to afford the fees to help them pursue their ambition as Stephen hoped to. It’s a big commitment – seven years of training. Four of the students the foundation has helped have now qualified, and there are 90 other alumni.

In recent years, as the foundation’s most reliable funding has been withdrawn by the closing of the London Development Agency, it has become much harder to guarantee this work. Lawrence used to be able to employ 15 people here, with an ambitious programme to help educate and implement the findings of the 1999 Macpherson report into Stephen’s death. She is now down to three full-time, and a few volunteers: the big society in action. She recently had the home secretary here and told her what she thought.

“All politicians make positive noises to us,” she says, “and this coalition government is no different, but in my last meeting with Theresa May I did have to say, you know, I felt I had been really let down. She met some of our students and was saying how wonderful the work was, and so on. I didn’t feel I could let that pass. After losing Stephen, I don’t feel I have much else to lose in life, so I try to speak my mind. I don’t remember her saying very much in response. Though to give her her due, later on they did contact the trust and we were given some emergency financial support to keep us going until March. It is very tough, though.”

I have come here armed with a long list of questions from Observerreaders, most of which are prefaced by tribute to Doreen Lawrence’s spirit and dignity. In person, you have a clear sense of that determination, her ongoing mission, her refusal to despair. It is that determination that has now seen two of the perpetrators of her son’s murder behind bars; it is a relief to her that one of them, Gary Dobson, has dropped his appeal against last year’s conviction, though the other, David Norris, is pursuing his case. She has learned by long practice not to dwell too much on any of that, she says.

We talk a little about her Olympic experience last year, when she was invited by Danny Boyle to help carry the flag in the opening ceremony alongside Ban Ki-moon, secretary general of the UN. “When they asked me I was really excited,” she says, “because though I had applied for tickets in the ballot, I didn’t get any. And on the night itself I got very emotional just standing there and thinking of all the millions of people watching and the world coming together.” The inclusivity of that ceremony and the Games were an expression of London at its tolerant best, she suggests, a statement of how far we had come in the past two decades, though she is obviously close enough to the reality to realise her home city doesn’t always live up to that ideal.

Her role in effecting those changes, the role that she was forced into by her son’s death, still seems often surreal to her, though she does not step back from its responsibility. “It’s funny,” she says, “I was in a school in Sydenham recently and they told me I was their ‘live history’ lesson.” She smiles. “They were doing their GCSEs and I was part of their coursework apparently. How strange is that?”

The oddness clearly feels a bit like her fate, these days, but she is not without hope or purpose. She answers the questions our readers have asked in that spirit.

Is London/the UK in 2013 a better place to be a young black man now than in 1993? Youcantalan, via email

That depends on which young black man you speak to. When Stephen was killed my whole idea of London changed. I used to see it through rose-tinted glasses. I had never imagined racism would take anyone’s life. I used to talk to Stephen about not getting involved in certain things, but he was always, “Mum, I’m not doing anything!” I think that is how a lot of young black men feel still today. But that doesn’t stop them being harassed in stop and search, or if they drive a nice car it is always assumed they are drug dealers. That is as true now as it was then. If I ever see anyone stopped on the street, it is invariably still a crowd of white policemen around a young black guy.

Did you experience racism when you came here to live with your mother, from Jamaica, as a nine-year-old? Name and address supplied

Not really. I went to primary school here. I wouldn’t say there was a problem, though if they showed a documentary at school about Africa or something kids would ask me: is that what it is like where you come from? The teachers weren’t overtly racist but it was clear, too, looking back that we weren’t always given the same opportunity. We would be put in for CSEs rather than O-levels. Or when we had careers advice it was always, “Are you good with your hands?” Most of my friends just ignored all that, though, and found our own jobs. I worked in a bank for seven years before I had Stephen. A lot of it was just kind of what you got used to. My younger brother told me he would make sure he stood apart from people at a bus stop or whatever, because he thought they might accuse him of being a pickpocket, or of trying to steal something. But overt racism: no.

You are such an inspiration and a fine example that persistence pays, particularly if accompanied by dignity and honesty. How do you keep going when there is so much venom aimed at you? How do you get past the negativity and always have something positive to say? Barbara Moss, via email

I do get some venom. We get hate mail here, and stuff posted on the websites. My real fear is more when I am on the street. I get recognised and sometimes people will catch me unawares and put their arms around me, or say they need to give me a hug. I find that quite alarming. I’m quite small and suddenly I am being crushed. It’s mostly positive, but there are a few who just stare at me. I do try not to be negative, though. I could have closed my door and shut myself away, but that is not me, and my children were not brought up that way.

In your fight for social justice and justice for your son, you and your family must have suffered. Isn’t it time for you to take some time out for yourself? No criticism intended – I think you are amazing – but you need a break. Gail Kirkland, Edinburgh, via email

I definitely agree with that! When I started working at the centre, I thought I’d do it for about three years and then hopefully hand it on to others. I thought I might retire to America or somewhere and live out the rest of my days quietly. But my life has not been like that. I realised that if I wasn’t here the work wouldn’t exist. I still want it to survive on its own, so I carry on. I travel up and down the country for the trust. I don’t do holidays much. As time goes on, the work of the trust just gets more intense. It is harder and harder to get away.

What do you think are the main reasons for the lack of success of black boys in education – and the high rates of unemployment, prison sentences, and rates of serious mental illness among the black community? RabBurnout, via website

That’s really a question about social justice. There isn’t just one thing you can point to. Yes, boys need strong role models to give them a sense of what they can achieve. I read something the other day about a teacher saying of black boys that “they have the bodies of men and the brains of children”. You wonder: how is this person fit to teach kids? Parents have a big responsibility too. When I had children, I thought it was important for them to be children, not to grow up too fast. Still, when my kids came home from school in the evenings we would always have the dictionaries out while I was cooking; I would be giving them spelling tests and word tests. My kids all got fed up with me not letting them hang out with their friends on the street. I would say: “They are out there today, they will be out there for ever. This is what you have to do to make sure you don’t end up like that.” I don’t think it matters who says that to kids as long as someone does. To say that single parents can’t do that is so wrong, as the likes of David Lammy will tell you. He was brought up by his mother on an estate in Tottenham and he went off to Harvard and became an MP.

The Macpherson report recommended “that consideration be given to amendment of the national curriculum aimed at valuing cultural diversity and preventing racism, in order better to reflect the needs of a diverse society”. In light of Michael Gove’s new history curriculum, how successfully is our education system meeting Macpherson’s recommendations? Martin Spafford, via email

I hated history at school, because it had nothing to do with me. We were taught about empire but not about slavery, what our grandparents and great grandparents went through. I wanted the Macpherson report to ensure that we opened up history lessons so all the kids in the class knew where they were from. If kids just hear that these people are over here taking our jobs, they will believe it. If they hear that in the past Britain has exploited every single aspect of the places where these children come from, then perhaps they will see things differently. Black boys in particular have a sense that their self-worth is not much; we need to change that. All children should have an understanding of the forces that created the country we all live in today.

What was your idea of Britain before you came here – a promised land? Richard Adams via email

No, it was more how cold it was, and how cramped. In Jamaica we had a yard and fruit trees. I used to think of Britain as a place of red brick huts with fires in the middle and all the people huddled round, and when I came here that is quite a lot how it felt. It was the summer but it was freezing. I had no cardigan, just a summer dress. And all the houses joined together, and people letting dogs inside the house, living with dogs; I couldn’t understand that.

What is your favourite memory of Stephen? It’s the question I love answering about my brother Ben [Kinsella, who was murdered].Brooke Kinsella, via email

There are many, of course. Stephen has a particular look. My daughter Georgina made me a calendar once. And each month had different pictures. For December there is a picture of Stephen the Christmas before he was killed. We had a washing-up rota at the time and it so happened that Christmas Day was Stephen’s turn. The picture is of him surrounded by all these pots and pans saying: “I can’t believe this is happening!” It was very funny. He has a way of being mischievous. He looks down then he looks up in an amused way. That is just Stephen for me.

Did you ever feel paralysed by anger at the injustice? If so, how did you overcome this? Susan Shaw, via website

I always tried to busy myself with something. In the early days I did focus on the anger – it was like I was locked in a room with it for 24 hours a day. I didn’t want to be in that place so I don’t go there.

Some years ago, you undertook a counselling degree at the University of Greenwich. What motivated you to do this, and how has it helped you personally and professionally? Christine Murray, via website

I did it because I wanted to understand more about the grieving process. For a couple of years after Stephen died, I had no counselling myself. I thought it would take me to too many dark places. But then I had therapy for probably a decade. I took the opportunity to study that process because I thought it would help me, and it did.

I am a serving police officer and qualified police trainer. In my view many officers are unconsciously incompetent because their training is often inadequate. Will you be working will the College of Policing to ensure officers are better equipped to understand the cultural issues that lead to mistrust of the police? Peter Clarke, via email

I certainly will do if I am ever invited to. I have never really been asked to be involved with the police. Just once, when I went to a senior police training role play thing. When I was there it seemed that their behaviour was very defensive, very quiet.

How did it feel to stand in front of Chris Ofili’s painting No Woman, No Cry? Nicola Churchward, via email

I didn’t stand in front of it for years after it was made. I read that Chris Ofili had won the Turner prize, and I knew about it. I eventually saw it at Tate Modern and it is an amazing painting. Each tear drop has Stephen’s face in it. I suppose at the time I was proud, or rather honoured, that somebody had been moved to do that. Chris Ofili I have got to know a little; he is a great source of energy.

My friends’ teenage son was killed six months ago. It was as a result of an accident, rather than an act of violence, but from your own experience, do you have any words of advice about how his parents might make their peace with such a terrible loss? Name and address supplied

Time hasn’t been that much of a healer. And for me, the violent way in which Stephen was killed made it very hard to come to terms with. The pointlessness of it. But you do have to find ways to remember who your child was as a person. I always have pictures of Stephen around, and I always talk about him; I never want to think that he never existed. At first, I just kept asking why did God let this happen, why did he not protect Stephen? For a long time I used to go to the church where I had always gone, but I would sit at the back and just slip in the moment the service started and as soon as it finished I would leave. I didn’t really want to speak to anybody and people found it hard to speak to me, I think. As time has gone on, I’ve begun to have a bit more understanding that through his sacrifice a lot of positive things have happened. People say to me sometimes if it wasn’t for the work we had done their lives would be harder. I take some comfort from that. The fact is a death is a death, however it happens. You have to find some way of looking back on the positive things in the person’s life before that happened.

Would you ever consider being a member of the House of Lords or even standing as mayor of London? Name and address supplied

I question what some people in the House of Lords are really there for. But of course I would like to be able to challenge some things that go on in government, to speak up on some issues. I think a lot of people do it for the glorification or whatever, but that would not interest me. Mayor of London: I don’t think so.

After two decades of amazing work, are we getting to the point where anti-racism campaigning is perhaps too focused on Stephen, such that our point of reference is 20 years out of date?Patrick Neylan, via website

I don’t think anti-racism is too focused on Stephen. When I speak I make a point of trying to speak about all young people. His name has become a useful reference point for people to talk about these things. The Macpherson report is a major inquiry, and I don’t think it is in danger of overshadowing the other issues.

How do you feel knowing that another 106 people have died in attacks with a possible racial motivation since the murder of Stephen and the inquiry into his death? Harmit Athwal, Institute of Race Relations, via email

Obviously every death is terrible. Many times mothers have written to me and contacted me. The mother of Andre Smartt-Ford, who died at Streatham Ice Rink in 2007, for example. I try to give as much support as I can. I can’t promise to get involved in everything because there is only one of me, but I have tried to speak out on behalf of other mothers and other victims.

I sometimes think, talking to my own teenagers’ friends, that race is not discussed enough among white families. If there was one thing you would say to other mothers about the way we discuss race-related issues, what would it be? Subistar, via email

It is every parent’s responsibility to discuss these issues and to ensure that their children are tolerant of those around them. This country was never a country for some mythical English white people; it has always been a mix. I would just say that people need to know their history.

How do I handle less open-minded attitudes when someone makes a comment that could be deemed racist? James Aldworth, New York, via email

Always challenge it. If you hear a child in a playground making a racist comment, you speak out, you never let it go.

What are your feelings towards your son’s killers? I doubt I ever could, but do you think you could forgive them for what they did?Perrylee, via email

You can only forgive those who seek forgiveness. They still don’t admit they have done anything wrong, so I don’t see how I can forgive them. They have to say sorry before you can think about forgiveness. They have never said that and I don’t imagine they ever will.

Do you think institutional racism against British Muslims exists in this country? begmohsin2, via email

It is a problem. As soon as you start talking about people in groups, then that kind of behaviour starts. Some young black men may be into drugs, but the majority are not. Some young Muslims may be sympathetic to terrorism, but clearly most are not. The racism arises out of that.

Like you, I am a strong supporter of the public sector equality duty. Its predecessor, the race equality duty, was motivated in large part by Stephen’s murder and is widely thought of as the most innovative development in equality legislation since the 1970s. So why do you think the government considers the duty to be “red tape”, and what do you think of the current review that has raised the suggestion that the duty might be scrapped or further watered down? Dr Hazel Conley, Centre for Research in Equality and Diversity

The public sector equality duty is the only measure we have to hold institutions to account over issues of race, but the review wants to make it seem as though it is about the bureaucracy of form filling. It is a bit like the recommendations from Macpherson about stop and search, the necessity of providing a paper basis for the reason why you had been stopped, so you could hold an officer to account. They have done away with that and they seem to be trying to do the same here. We are moving backwards rather than forwards.

How do you feel about the “reclaiming” of the “N” word and, particularly, the frequency with which it is used in rap? Jo-Anne Welsh, via email

I think it is more of an American thing than a British one. I don’t listen to rap music, so I don’t really have a view. I guess kids can be influenced, but not always. Stephen was a music fan; he liked Mariah Carey and some urban music such as Public Enemy. But I don’t think it had much of a bearing on how he behaved.

How do you see the current state of race equality in Britain, especially considering the negative rhetoric surrounding human rights, immigration and asylum policy? Shami Chakrabarti, director of Liberty

This government could have built on Macpherson, and they haven’t. When my son was murdered the Conservatives were in power and they did nothing. And it seems in coalition, now, they still don’t do anything. I have not met David Cameron in the way that I met Blair and Brown. Politicians always seem to want to blame immigration for the problems of the country. Immigration policy has to be fair, but you have to keep making the arguments against that blame culture. We need younger people to be taking up the battle for these issues. I went over to Washington for President Obama’s first inauguration. It was something I never expected to see in my lifetime, a black man running a country like the US. I needed to be there to witness it, one of the 2 million. I don’t think I will ever see it happening here, though. There are plenty who could do it, but I don’t think we would give them the opportunity. They would never think you are good enough, not really.

The Stephen Lawrence Charitable Trust is dedicated to providing opportunities for disadvantaged young people and maintaining Stephen’s legacy. To give money, go to justgiving.com/slct/Donate. stephenlawrence.org.uk