Washington, May 17 : English actress Sienna Miller has admitted that her sister Savannah's pregnancy is making her desperate for a baby.

Miller would like to start a family of her own with actor boyfriend Rhys Ifans, and she says that it is her sister's attitude which has inspired her to want a family of her own.

"I really want bubbies (babies) - I always have. I mean, I'm nearly 27 and you have to think about these things, don't you?" Contactmusic quoted her as saying.

"Sav (sister Savannah) proves you can work and be a mum. It scares me, though," she added.

Meanwhile, Miller has ordered fiance Rhys Ifans to bulk up his frail frame before they get married this summer.

The 26-year-old stunner, who has dated the likes of Jude Law and Bond star Daniel Craig - definitely knows how to pack out a pair of tight-fitting trunks.