Sienna Miller’s pregnant sister Savannah has shared a sweet snap of their matching bumps as she approaches the ‘finish line’ of her IVF journey.Taking to Instagram on Sunday, the fashion designer, 47, happily documented her pregnancy as she shared a number of photos of her growing stomach throughout the months. Among the images were a snap of Savannah and Sienna touching their bare bumps together, while Savannah also slipped into a black bikini to showcase her growing belly.Savannah’s actress sister, 44, has already welcomed her third child back in May, while Savannah’s child, with second husband James Whewell, is thought to be due in late August. Meanwhile, proud mum-to-be again Savannah, who is expecting her fourth child, shared a plethora of selfies showing how much her bump has grown as she counts down to the birth.The timeline of pictures showed the very beginning, with Savannah uploading a photo of her positive pregnancy test, through to her recently being almost at full term. Sienna Miller’s [left] pregnant sister Savannah [Right] has shared a sweet snap of their matching bumps as she approaches the ‘finish line’ of her IVF journey Taking to Instagram on Sunday, the fashion designer, 47, happily documented her pregnancy as she shared a number of photos, including one of her showing off her belly in a black bikiniShe looks to have thoroughly enjoyed her pregnancy, with snaps of her on holiday, sunbathing, working out and making the most of the summer sunshine.Captioning her heart-warming post, she penned: ‘From December, the day of our embryo transfer, to today…. Approaching the finishing line with the cooking of this gorgeous egg. We can’t wait to meet you little guy!’ It comes after Savannah said last month that she saw her sibling’s pregnancy at 43 as a ‘sign’ to have a fourth child in her forties after remarrying.The British designer, 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 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’s actress sister, 44, has already welcomed her third child back in May, while Savannah’s child, with second husband James Whewell, is thought to be due in late August [pictured together in 2025] Meanwhile, proud mum-to-be again Savannah, who is expecting her fourth child, shared a plethora of selfies showing how much her bump has grown as she counts down to the birth The timeline of pictures showed the very beginning, with Savannah uploading a photo of her positive pregnancy test, through to her recently being almost at full term She looks to have thoroughly enjoyed her pregnancy, with snaps of her on holiday, sunbathing, working out and making the most of the summer sunshine Savannah documented her growing stomach throughout the months She displayed her bare bump as she soaked up the sun on holiday Savannah looked ready to burst in one bump photo Captioning her heart-warming post, she penned: ‘From December, the day of our embryo transfer, to today…. Approaching the finishing line with the cooking of this gorgeous egg’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.’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.'”