Her spirituality is something she found when she was in prison. "It means I have a right as a woman to be who I am," she says.
Those who have followed the story of this battered woman who killed her husband will see her stone and declaration that she is now a "soul'' here to teach peace and harmony as evidence of the "madness" that prompted her to kill her husband, Malcolm. Others may see it as an example of her need to attract attention - a feature of the personality disorder she suffers which renders her liable to severe mood swings and sometimes inappropriate reactions. Sara sees it as her salvation, an indication that her life and Malcolm's death have some meaning - a sign that people can change.
With a woman so full of complexities and contradictions, there are no simple explanations. That is why she became a champion for the battered women's cause, only to be later sidelined because she but did not play the part of the helpless victim. She fits no stereotype and can be her own worst enemy.
A tiny woman, about five foot, and terribly thin, she bounces in from a shopping trip. "I've had so many people say how happy they are that I am free. I have had so much support. It means so much. I need that support."
It is one of her many contradictions. In another breath she says: "Do you think my feelings of self-worth depend upon the press coverage or what Malcolm Thornton's family think of me? No they do not. It doesn't hurt me, it hurts them."
But despite the tough words there is the impression that Sara does hurt and very badly: her body language betrays the conviction in her voice, a gentle rock or a sudden leap up and out of the room when we touch on raw nerves.
Sara Thornton became a household name, when her first appeal against her compulsory life sentence for the murder of her husband, stabbed while he lay in a drunken stupor, failed. Her case highlighted an apparent discrepancy in the law which allowed men who acted in sudden anger a defence of provocation - even if the provocation was trivial. But it was denied to women, particularly battered women, who might have finally snapped after a long, slow build- up, but could not show the necessary "sudden and temporary" loss of control.
Her case raised public awareness of domestic violence (it accounts for one in four violent crimes) and placed reform of the homicide laws on the legal and political agenda.
Other women, such as Kiranjit Alhuwalia and Emma Humphreys who killed violent partners, benefited and were freed by the appeal court after their murder convictions were reduced to manslaughter. Last year, Sara's conviction was quashed by judges who ordered a retrial for murder. Although she was released on bail from prison where she had spent five years, she risked being sent back.
Last week, an Oxford jury convicted her of manslaughter after being asked to consider two options - that she was provoked by her husband's alcoholism and violence, or that her responsibility was diminished because she suffered from a personality disorder. Although no one knows on what grounds the jurors reached their unanimous verdict, the judge sentenced her to five years, finding diminished responsibility.
That makes Sara very angry. "The judge had no right to do that. He didn't know what the jury was thinking or how the verdict was reached. But it was politically expedient because people would rather think I did it because I was mad than because society let me and Malcolm down. Everybody knew - his friends, the police - that he was ill, that he was drunk in alleyways, that he threatened to kill me. But nobody cared about him before his death - only afterwards."
Sara agrees she suffered less abuse than some women, adding: "Kiranjit was not battered, she was tortured. What are you saying? That there are levels of battering which are acceptable?"
In another contradiction, she blames neither Malcolm nor men for domestic violence. "Malcolm and I were a disaster waiting to happen. We were mirror images of each other. He abused me because I abused myself," she says. The five-year jail term was fair.- but she adds: "It is only fair if men start getting that kind of sentence as well." She is right again. "What sentence do you think Malcolm would have got if he killed me?" she asks.
"What everyone forgets is that I loved him and he loved me and that between these episodes we had some really good times."
Sara chose not to give evidence during her second trial, because she says she has talked so much about the killing - particularly to psychiatrists - that she sounds like one, herself. "I honestly do not think I could have given a true account of what happened.
"All I know is that I didn't mean to kill him. I mean I am supposed to have this extreme personality and I would have stabbed him loads of times if I meant it - not just once. I know I was at the end of my tether, I was angry. I was frightened. I don't know, it was crazy."
Certainly her behaviour immediately afterwards was bizarre. She called an ambulance, put some washing on, patted the bottom of the policeman who arrived and offered to cook everybody pasta.
Surprisingly, her father, Richard Cooper, gave evidence for the prosecution. Asked why, she gets up and leaves. "I can't talk about that."
She was born 41 years ago into what should have been a South Seas children's idyll of beaches and blue skies. Her father worked for the British Government on the Pacific islands and her mother, Jane, was a marine biologist.
But she and her sister Billi, grew up in a house echoing with turbulent rows between their parents. The father is portrayed as a distant figure and, although he denies it, the daughters say their mother was violent.
The girls withdrew, forming the bond that still holds them together. They are said to have handled rejection and their quest for affection differently: Sara becoming volatile and rebellious, Billi withdrawn.
Sara made several attempts at suicide - the first as a teenager, the last in her 20s. The scars across her left wrist, and even more alarmingly on either side of her neck, show she was serious. It was, she says, because she was consumed with a sense of failure as a daughter and a mother
She will not speak about her father, but she does talk of the violence dished out daily by her now-dead mother - painful testimony supported publicly during last week's trial by Billi, also estranged from their father.
Was Sara ever happy? "I was when I gave birth to Luisa [her daughter by her first marriage] . . . And there were other times. But I am not a very happy person. I am not happy now."
And what of her future - now she is finally free? She is reluctant to seek counselling but is convinced her turbulent history will never repeat itself. She will attract a different type of man. And here we return to her New Age spirituality. "Prison was good for me. I was harsh on myself. I went into prison as someone who had taken a life and I used my pain to heal myself. Now I want to go back to prison and teach meditation and healing to people who have time to look at the patterns and beliefs in their lives that allowed to them to make problems and mistakes and make the changes for themselves."
But she will take no responsibility for causing Malcolm's family - in particular his son, Martin - any pain. They must also accept responsibility as she has done, she says. "If Martin wants to project his pain on to me as being the evil woman, that is his responsibility. But that will destroy him in the end - not me."
And then suddenly the hard tone fades again and she says: "I am trusting you with this. What you write about me becomes fact with a lot of people."
But, after only a very brief spell with Sara, there can be few hard facts. Only the impression that underneath this woman who presents a strong, confident and sometimes rejecting facade, there is an unhappy and very vulnerable person, looking for love and - despite her bravado - understanding. She is someone who needs a hug.
n People can assess Thornton themselves when she tells her story in "Provocation" - a Cutting Edge special - on Channel 4 on Thursday 13 June at 9pm.Reuse content