Savannah Miller, 47, reveals her sister inspired her to have another baby as she opens up on her 'complicated' fertility journey

Sienna Miller's sister Savannah has said she saw her sibling's pregnancy at 43 as a 'sign' to have a fourth child in her forties after remarrying.

The British fashion designer, 47, who was already mother to Moses, 21, Lyra, 18, and Bali, 14, from her first marriage to Nick Skinner, said that her sister's attitude towards motherhood and life in general made her realise she could 'handle' another baby.

Sienna announced she had given birth to her second child with her fiancé Oli Green, 29, in 2024 and Savannah said she began to believe she could 'do it again', and by the time the actress announced her third pregnancy, Savannah said she was 'all in'.

Savannah met her second husband, James Whewell, six months after splitting from her ex-husband Nick and they married in a 'magical' ceremony in 2022.

They began to discuss the possibility of having a child together and Savannah said how James told her that he would be happy with whatever decision she made.

The couple, who are expecting a baby boy, announced that they were set to become parents in March following a 'complicated' fertility journey.

Savannah said that they have chosen not to disclose how their unborn child was conceived, because they feel it is their child's right to decide whether they want to share it. 

Speaking to British Vogue about her decision to have a baby, she said: '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.'

'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.'

Earlier this month, Savannah and James enjoyed a babymoon before their little one arrives in August.

In photos from their getaway, Savannah looked radiant as she relaxed with her husband at The Pig-near Bath.

The couple relaxed during the break, with Savannah sharing snaps of the couple exploring gardens, eating ice-cream in the bath and posing in front of paintings.

When she announced their pregnancy, Savannah shared her joy at being pregnant at the same time as her sister Sienna.

Sharing photos of her baby bump, Savannah said: 'Our longed for miracle baby is joining the gang in August!

'To be able to relive the magic of pregnancy, with Jim, who is the most deserving and dedicated dad already to my three, is a profound and phenomenal gift.

'Now I know how brief it all is, on the cusp of my firstborn's 21st birthday, I hope to be able to slowly savour the innocence and wonder in every minute. 

'To be doing it all over again at the same time as my sister is the most delicious cherry on the icing on the cake.'

Speaking more about her pregnancy at the time, Savannah admitted falling pregnant at the same time was 'intentional'.

Savannah said: 'It was intentional on my part. I thought: 'If she's doing it again, at least I won't be in the trenches on my own. I'll join her… if I should be so lucky.'" 

Speaking to Hello! about the stigma of women having children 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 was previously married to Nick, a bushcraft teacher from Devon, and was stepmother to his son, Java Skinner, 31.

James is the heir to the Wyresdale Park estate in Lancashire, which the couple now run as a wedding venue.