Sienna Miller's older sister Savannah, 47, shows off her bump on her babymoon after revealing her actress sibling's third pregnancy inspired her to have her fourth child

Sienna Miller's pregnant older sister Savannah, 47, showcased her growing baby bump as she enjoyed a swanky babymoon with her husband James Whewell.

The fashion designer, who is a mother-of-three with her ex Nick Skinner, looked radiant as she relaxed with her husband on Wednesday 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. 

In March, Savannah shared her joy at being pregnant at the same time as sister Sienna, 44 - who welcomed , at the end of April - and 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.'

In her announcement in March, Savannah shared pictures of her bump and wrote: 'Our longed for miracle baby is joining 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.'

Savannah shares Moses, 21, Lyra, 18, and Bali, 14, with her first husband, Nick, a bushcraft teacher from Devon, and was step mother to his son, Java Skinner, 31. James is the heir to the Wyresdale Park estate in Lancashire. 

Her babymoon comes as sister shared the first photos of the two children she shares with her fiancé. On Wednesday the Layer Cake star posted photos of their whirlwind first few weeks as a family, under the caption 'Adulting.'

The snaps show a blissful Sienna cuddling her newborn in hospital after the birth. The couple are yet to reveal her third baby's sex or name.

She also shared her first photo of the two-year-old daughter she shares with Oli, posting a sweet snap of her toddler's curly hair. 

In another photo a heavily pregnant Sienna rests in bed with her bump on show. Childhood photos of Oli along with toys and sports memorabilia cover the shelves, suggesting the couple retreated to his childhood home shortly before the birth. 

 Oli also appears in several photos, looking emotional as he held his baby in hospital before pushing the pram near the couple's London home. 

Oli shared his own look at the realities of life with a newborn on Wednesday, uploading selfies of himself with bags under his eyes alongside the caption 'parenting'. 

Sienna is now a mother of three, sharing daughter, Marlowe, 13, with ex-partner .  She announced her third pregnancy by revealing her blossoming bump at the star-studded  in December. 

In May, she said that she's surviving on 'very little sleep' as she opened up on returning to work just three weeks after giving birth while appearing on The Tonight Show With .

During her appearance on the show she opened up about the transition of having another child and spoke about her nightmare flight over to the US to promote new action movie Jack Ryan: Ghost War.

Sienna said: 'It feels like stringing sentences together is a bit challenging. I'm on very little sleep but I'm madly in love with my baby.

'It's crazy to be talking words and wearing a dress. What has happened from pajama gate.' 

Asked by the host which of her children are tougher to look after, she said: 'I would have said the teenage girl would be harder to juggle until the transatlantic flight I took yesterday with the toddler and the newborn.