Artist and director Sam Taylor-Wood and fiance Aaron Johnson have become parents to their second child together.
The baby girl has been named Romy Hero Johnson, with both mother and child said to be doing well.
Romy - born last week - joins 18-month-old sister Wylda Rae and Taylor-Wood's older daughters Anjelica, 14, and Jessie, five, from her previous marriage to art dealer Jay Jopling.
Kick-Ass star Johnson, 21, and Taylor-Wood, 44, met when she cast him as John Lennon in movie biopic Nowhere Boy in 2009, in which Anjelica and Jessie made cameo appearances as Lennon's younger sisters.
Despite the 23-year age gap, the couple became engaged after just a few months dating.
A statement issued on behalf of the couple said: "Sam Taylor-Wood and Aaron Johnson are the proud parents of Romy Hero Johnson, who was born at home in London on January 18. Both mother and daughter are well."
Taylor-Wood said in an interview last year: "Aaron, almost before anything started between us, said he wanted kids. He was very clear about wanting a family.
"We hardly go out now - it's just us. Aaron has brought a set of values I didn't even know I was looking for - family values.
"He is more grounded. He has been getting work offers which he has turned down because he wants to be here for the crucial first months of Wylda's life."
She has defended their age gap in the past, saying: "In the old days, 'controversial' in a relationship meant same-sex or mixed races. Now, it is a woman with a younger man. That would not happen with a man."
Johnson has said: "I'm an old soul and she's a young soul. We don't see an age gap, we just see each other."