There is a note of satisfaction as well as grief in the air as her three children Sophie, 41, Edward, 39, and Jessica, 37, tell her story.

They hold hands, grip each other’s shoulders, crying intermittently, make cups of tea and ignore the Duchy Original biscuits they have set on the table; they are sad but not desperate people in a time of loss.

Outside, the pretty village of Combe Down near Bath slumbers on seemingly unaware of the outrage and protests spinning around the house where Anne Turner lived her last years. Warm and modern, it was a relief to her after bringing up her family in the beautiful but draughty 1838 stone vicarage a few hundred yards away. Next door is Holy Trinity church where her memorial service will be held on Friday morning, a humanist service in a Christian church only too happy to celebrate the life of a woman who did not believe in God because she believed so strongly in people.

It has been a dizzying week for the children, Sophie, an actress, Edward, a chartered accountant who does most of the talking, and the youngest daughter Jessica, who prefers not to take part in the interview but tells me before she disappears that she doesn’t think the loss of her mother has hit her yet.

Since their return to Britain on Wednesday they have been deflected from the ravages of grief by proselytising, making the case for assisted suicide and answering criticism from those who feel that they helped their mother to do the wrong thing.

The hospice movement claims that with proper care a slow death can be a good one, but Edward’s response is vehement: “I find those comments annoying, they ignore the individual circumstances people find themselves in. If it is true for some people, then it is not for others. People say if we had good palliative care it would all be fine, if you have someone to turn you over every 15 minutes and up your morphine dose . . .

“But some people don’t want to lie in a darkened room on a featherbed unable to even blink. If they are high on morphine it may not be the life they want. I wasn’t for or against assisted dying but having seen it — and in a selfish way it meant I lost my mother — I would certainly want the choice.”

By assisting their mother’s travels to perform an act illegal in this country her children might have also acted illegally; although while Avon and Somerset police confer with the Crown Prosecution Service it is doubtful that action will be taken. If it were, Edward and Sophie would be willing to face the consequences.

“If there was ever a conflict between what is legally and morally right it is this situation. What we did is the final act of love and kindness any child can do for their parents,” says Edward.

“If it meant going to prison I would, absolutely,” adds Sophie, before her brother continues: “I have a lot to lose, a criminal caution could lose me my job, but if I were prosecuted it would be a price worth paying.”

Last Tuesday their 66-year-old mother, unable to face a future of untold debilitation, drank a lethal concoction of sodium pentobarbital in a flat owned by the Dignitas clinic in Zurich, which has helped 42 terminally ill Britons to die. Twenty-five minutes later, with her children holding her hands, she was dead.

SITTING close together on the sofa, conventionally dressed and beautifully spoken, the siblings are perfect ambassadors for the cause as Lord Joffe’s bill on assisted dying for the terminally ill passes though the Lords.