Former children’s laureate Jacqueline Wilson confesses that the passionate sex scenes in her second book for adults have left her wondering how friends and family will react.

“I have to forget that everybody who is a friend of mine or family might be going to read it, because otherwise you get tremendously hot under the collar and embarrassed about it,” the sprightly bestselling author of more than 100 books and creator of Tracy Beaker admits. “I just live in the moment of my characters.”

At 79, she has written Picture Imperfect, a follow-up to her children’s book The Illustrated Mum (adapted into a TV movie in 2003 starring Michelle Collins), which introduced the eponymous mum, tattoo-adorned Marigold, and her two daughters, Dolphin and Star as they try to come to terms with their mother’s depression and instability.

Book jacket of Picture Imperfect by Jacqueline Wilson (Bantam/PA)(Bantam/PA)

Fast forward two decades, and Picture Imperfect finds Dolphin, 33, now a talented tattoo artist, struggling to move on, living in a bedsit and trying to look after Marigold who has bipolar disorder and is hospitalised, while her sister Star is a doctor, and is seemingly not putting in enough effort to help, as she lives in Scotland with her family.

Dolphin hopes romance will save her and is torn between dependable but boring gardener Lee and his daughter Ava or exciting Lothario actor Joel. The sex scenes in the book range from functional to frantic, in tandem with the characters.

“I thought about this carefully because, well, if Beatrix Potter had suddenly started writing some steamy adult novel, because you get identified with your childhood characters, it would seem a little strange.

“But I thought, if I’m writing for adults, generally people do have sex lives, or want to have sex lives, or are quite happy not to have sex lives, but aware they are not having them. So I thought, this is part of life.”

“In my children’s books, there’s an awful lot about food, the picnic meals, the treats, and somebody said that in children’s books the place of sex is taken by food,” she continues. “So I’ve lots of food in the children’s books and a little bit of sex in the adult books.”

Septuagenarian Wilson writes as the 33-year-old narrator, Dolphin, and says it was difficult to find a contemporary voice of a woman 45 years her junior.

“I do remember quite vividly when I was 33, although my circumstances were very difficult (she was then married to Millar Wilson with a young daughter, Emma, who is now a Cambridge professor), difficult marriage, difficult circumstances, but I think basically people still have the same emotions inside.”

Tattoos feature heavily in the story, yet the lively, contemporary-thinking author confesses she’s never had one for fear that whatever was inscribed on the skin in youth would become less relevant with age.

“I meet many lovely young women whose legs contain many Taylor Swift tattoos. And when they’re my age, they might think, ‘Why do I have all these Taylor Swift tattoos amongst my varicose veins?’”

Mental health issues are also prevalent in the story, as Marigold has bipolar disorder and Dolphin is worried she may have inherited that gene.

Wilson has known people with bipolar disorder and researched the subject thoroughly, reading great medical tomes on it, and although she doesn’t want to romanticise the condition, she says that the right medication and a degree of self-care can help.

Famed for penning children’s stories with real-life gritty backdrops, whether it be care homes or council estates, dysfunctional families, illness, unemployment or mental health, she herself grew up in a fractious environment, the daughter of warring parents who ended up getting divorced, which affected her own mental wellbeing.

“I think deep inside I have a very anxious personality and I do catastrophise because often things did go wrong, even on holiday which was when my parents had their worst rows. It was a very turbulent childhood.”

Her parents had met during the war, in an era when the template for women was to get married and have children.

“Towards the end of the war, my mother charmlessly said, ‘I didn’t think much of your father, but he was the best of a bad bunch.’

“By the time I was born, they really would much sooner have not ever met, but in those days divorce seemed to be a much more uncomfortable thing.

“I suppose I’ve got a steely bit in me because I left home at 17 which was quite a challenge, and got this offer of being a journalist in Dundee. It was the making of me.”

Her upbringing affected how she approached relationships in adulthood.

“I wanted someone to love me and I got that by marrying early (at 19), because I had my daughter and I loved her immensely. She did return all that love and we’re still very close.

“But by the time I got to middle age and my marriage had broken up, I had a much more jaundiced idea about finding the right person.”

When she was in her 50s, her husband of 38 years, printer Millar Wilson, left her for another woman. They divorced in 2004.

By then she was a bestselling author – The Story Of Tracy Beaker, published in 1991, catapulted her to literary success – and later met Trish Beswick, a bookseller, on a literary weekend, and fell in love. They have been together for more than 20 years.

Five years ago, she wrote a same-sex fictional love story, Love Frankie, aimed at aged 10-plus, which drew attention to her own personal circumstances, although she said at the time it wasn’t a grand “coming out” as anyone who knew her was aware of their relationship.

She has since been described as a ‘gay icon’, a label she feels delighted about.

“I’m very proud of this. I’ve always had lovely gay friends without ever really thinking, ‘Am I gay?’ So I really feel very comfortable.”

Wilson’s first novel for adults, Think Again, published last year as a sequel to the Girls series, marked a significant LGBTQ+ storyline for the author.

“Because I have written about gay characters – in Think Again, Ellie discovers that she is gay, or falls in love with another woman – I’m just charmed by this new element in my life and very proud too.”

She has had major illnesses – heart failure, kidney failure (she had a kidney transplant a decade ago) but she is still keen to live life to the full.

There are no plans to bring back Tracy Beaker in a book for adults, although she’s written about Tracy as an adult in a book for children, narrated by Tracy’s daughter.

“Because I’ve written about Tracy in that way, I would have serious problems about suddenly writing about Tracy as Tracy herself and it would be weird getting right inside the adult Tracy’s head. I’m not even sure if I could cope with writing about Tracy’s love life. But I have learned, never say never.”

For now, she’s going on a book tour, has writing to keep her busy – and no thoughts of retirement.

“I’m going to try to do one adult novel and one children’s book a year,” she enthuses. “I’ll keep going on as long as I possibly can.”

Picture Imperfect by Jacqueline Wilson is published by Bantam, priced £22. Available now