Sienna Miller inspired her sister to have another baby.

Savannah Miller, 47, opened up about her "complicated" fertility journey in an interview with Vogue, as she said Sienna's three kids - Marlowe, 13, a two-year-old and a newborn - made her realise she could "handle" another tot.

Savannah, who is already mum to Moses, 21, Lyra, 18, and Bali, 14, from her first marriage, explained: "The longer I spent with my magical little niece, the more I realised how much I had changed since having Moses all those years ago.

"In my 20s and 30s, I had so much to prove to the world - and to myself; every day felt like a race that could never be won. Now, when I'm with Sienna's younger daughter, I feel a lot more present, all of my urgency replaced by a sense of how quickly the years pass, no matter how long each day feels."

Savannah is now pregnant with her fourth child, and admitted that while she was initially scared of having another baby aged 47, she soon realised her age is actually a pro.

She continued: "For so long I thought that having another baby in my 40s would mean beginning the motherhood journey all over again - but actually, I realised, I'd be starting from a completely different place this time: a place of much deeper wisdom about parenting and with a completely different partner by my side.

"When Sienna told me in 2025 about her third, it felt like a sign. If we should be so lucky for it to happen, I was in."

While Savannah and husband James Whewell have opted not to reveal how their baby was conceived, she did say previously that falling pregnant was "intentional".

She also added to Hello! magazine that she's fed up of the stigma surrounding women falling pregnant later in life.

She said: "There's a very strong narrative against women doing things...

"It frustrates me immensely, because if it were a man, the question wouldn't arise; it doesn't enter people's heads.

"If it's biologically possible, then clearly it's totally fine. People are always going to have their opinions, but each to their own."

Savannah's "miracle baby" is due to make their big entrance into the world this August.