Sienna Miller welcomed her second child, a daughter, with boyfriend Oli Green in January 2024. This marked her first child with Green, a significant milestone in her journey to expanding her family. The couple has yet to publicly share their daughter’s name.
The actor, now 43, first publicly revealed her pregnancy in December 2023 at the British Fashion Awards. She appeared radiant, showcasing her baby bump in a sheer, strapless white Givenchy gown, with Vogue Magazine confirming the news on social media that night.
Her path to this new chapter of motherhood follows years of candid reflection on fertility and the pressures women often face. Two months after she was first linked to Green in 2022, Miller disclosed that she had frozen her eggs when she turned 40, a decision driven by the “pressure” to have more children.
Miller spoke openly about the biological challenges, telling Elle UK at the time, "Biology is incredibly cruel to women in that decade [their 30s], that’s the headline, or at least it was for me. Then I got to 40 and I froze some eggs." She added that this step alleviated an "existential threat," allowing her to adopt a more relaxed approach: "if it happens, it happens."
In November 2022, Miller shared further insights with British Vogue about her desire for a larger family. She spoke of losing "important years" and feeling that "time really was my currency," acknowledging anxieties about relationships that hadn’t worked out and an imagined future of being "married, with three kids, being a great mum."
Miller’s relationship with Green, who is 14 years her junior, began in 2022. She told Harper’s Bazaar in June 2024 that she initially "didn’t expect to take it seriously." However, she quickly fell in love, admitting her surprise at his age. “It wasn’t like: ‘I’m going to go and get a younger boyfriend.’ It was more, ‘F***! Why are you young? That’s so annoying.’”
Despite the age difference, Miller finds it to be a positive aspect of their partnership. She highlighted a generational shift in how younger men respect women. "There is a difference in the way that generation of men respect women," Miller observed. She described Green as "very much his own thing, he’s very wise and balanced, but I also think that’s of that generation. They’ve grown up with a slightly more equal playing field. I see it in his female friends as well as the men." Miller’s elder daughter, Marlowe, was born in 2012 during her previous relationship with Tom Sturridge.