The arrival of 21-year-old Assisi's baby at the end of April will make her mother Jade a grandmother at the age of 42 – and her grandfather Sir Mick a great-grandfather for the first time.
Announcing her pregnancy to HELLO! Magazine about the impending arrival, she says that giving birth at a young age runs in the family; Jade was just 20 when Assisi was born.
"The women in our family just tend to have children young, it runs in the genes," said Assisi, who lives in Cornwall with her boyfriend of three years, chef Alex Key, 25.
"I grew up quite quickly and wouldn't have considered having a child if I was doing what my friends are doing at this stage, messing around," added Assisi. "I don't drink, I don't smoke and I'm very settled."
Jade paid tribute to her daughter's nurturing skills. "She'll be a perfect mum," said Jade, marrie art director and graphic designer Adrian Fillary last year. "Assisi is a level-headed, sweet girl and I think it will give them both a lot of pleasure. It gives you an amazing purpose in life, to fulfil nature's destiny." Assisi's father is Jade's former partner, artist Piers Jackson.
Assisi said that her Rolling Stone grandfather was delighted to hear the happy news when she telephoned him to say she was pregnant.
"He said, 'Well done,' and I said, 'I didn't have to try too hard.' I imagine it's nice to be a great-grandad – although I'm not sure he likes the idea of getting old, or being called one. I call him Mick – I wouldn't start calling him grandpa."
To read more of the interview with Jade and Assisi, pick up the latest edition of HELLO! Magazine issue , out now.