Sarah Ferguson had just turned 12 when her mother came to her and said simply "I'm off now," and left for Argentina, never to return. Sarah saw her a handful of times after that, once when her older sister married and then promptly emigrated to Australia; and once for the funeral of Sarah’s close friend Diana, Princess of Wales. Sarah’s mother Susan was killed in a car accident in Argentina just a year after Diana’s death. Speaking to Brendan O’Connor, Sarah says the breakdown of her parents’ marriage meant that neither of her parents were there for her when she needed them:

"How it left me, Brendan was that Dad was so broken by the loss of his wife and the failure of his marriage, that he was never present, and so I was alone. And that made me turn to food and I became obsessed with comfort eating."

Self-pity was strongly discouraged in her family and Sarah says she just got on with life. She knows that her existence was a privileged one, but Fergie says her childhood distress was dismissed and she had no-one to talk to about it:

"You can’t express yourself. You know: 'Shut up, no-one wants to hear from you, go away, you’re very lucky, just go and get on with it.’ It was a thing in those days not to express your emotions. I suppose that’s why it has been very difficult for me because I am full of joy, and I am full of why and full of curious life."

At 26, she fell in love with King Charles’ younger brother Andrew, who she describes as "an extremely good-looking prince". They were married just over a year after becoming a couple. Two children, a separation and a divorce all followed within ten years, but Sarah and Andrew have continued to share a home as co-parents of their two daughters. Even after the daughters have grown, the pair still live under the same roof. Sarah says she developed a close relationship with her mother-in-law, the late Queen Elizabeth II:

"She was more my mother than my own mother."

Fergie and The Queen bonded in recent years over their shared support for Prince Andrew, who came under constant media attention, following accusations of trafficking and sexual assault: allegations which he denies. Fergie says she and Queen Elizabeth used to call each other "bookends," because of their dual role as Andrew’s supportive tag-team. Sarah says that her former husband, Prince Andrew stood by her when she had tough times. She still has faith in him, she says:

"I still believe that he is a good father and a very good grandfather, and he stood by me, and I’ll stand by him."

Sarah says she was idealistic about her relationship at the time she got married, as was her good friend Diana, Princess of Wales:

"We both believed in the love of our marriages."

Fergie and Diana were close friends, but the press were constantly tearing them down and trying to pit them against each other, creating a conflict that never existed. Both Sarah and Diana were dragged in the tabloids for their looks and behaviour, with Sarah coming under fire over perceptions that she was overweight; particularly after the birth of one of her daughters. She was called ‘The Duchess of Pork’ and ‘Fat Fergie’. The body-shaming was savage and it got to her, Fergie says:

"And I admit yes, I'm very vulnerable sometimes when it hurts, it does hurt. And that’s probably when I would reach for the cookie jar, as they say."

She describes the way she and Diana were treated was ‘diabolical.’ Neatly segueing to another famous woman who married a royal and was targeted by the press, Brendan asked Sarah if she could understand why Meghan Markle would want to ‘bolt’ from the royal spotlight? Fergie’s spontaneity gives way to a carefully crafted reply:

"You’re so clever, Brendan. You’re so clever. What a loaded deck! How I will answer you Brendan is exactly the truth. The American people have always been extraordinary supportive of me and my family. And I love the way that she loves Harry and makes Harry happy and that’s why I have no judgement in any way shape or form. And I do support and uphold what I think is good; I think Harry and Megan are extremely happy and have beautiful children and I wish them well."

Like other members of the British Royal Family, Sarah spends a lot of time on philanthropy and in recent years, she’s found a new career as a novelist:

"Forget Duchess, wife, ex-wife, mother, grandmother, all that. I am becoming an author. I’m 63, starting a new career. Very proud of it."

She’s been writing historical fiction, loosely based on the lives of some of her female ancestors; who she says were ignored as ‘mere women’ when they were alive, but who deserve their place in the sun, she says:

"For 25 years I’ve wanted to write a novel, because I wanted to get my ancestors with red hair out of the grave, poor loves! Everybody wrote about the boys and nobody wrote about the girls – because they were women. In 1872 they though nah, forget about those women, they are irrelevant!"

The best advice Sarah ever got was from her father-in-law, the Duke of Edinbugh. Sarah says they shared a love of carriage driving. He advised her on how to behave in public as a member of the Royal Family:

"’Every single thing you do will be on the front pages, so think.’ And he always said ‘You always need to be electable and you’re never elected.’ I wish I’d listened to him more."

Sarah Ferguson talks about her Irish side, why she fought to have Mills and Boon as a publisher, her plans for the coronation, and her predictions for the reign of the UK’s King Charles III in the full interview here.

A Most Intriguing Lady: A Novel by Sarah Ferguson is published by Mills and Boon.