Sienna Miller is Poppy Delevigne's style "heroine".
The pregnant actress and the 25-year-old model are now close friends but Poppy admits that, before they met, she always wanted to "look just like" the 'Factory Girl' star and worries her obsession freaks out her pal.
She said: "I remember when Sienna Miller's first Vogue cover came out, just after she was in 'Alfie' and before I knew her. She looked so dreamy in white and she had feathers in her hair and that whole boho thing going on.
"She was totally my heroine at the time, I just wanted to emulate her. And now of course we're friends and I'm always telling her how I wanted to be just like her - she probably finds it quite scary."
Poppy's younger sister Cara is also a successful model and the British Fashion council young ambassador says her family always knew her 20-year-old sibling would grow up to be beautiful.
Poppy told Vogue.co.uk:"Cara was just the sweetest little thing, growing up. She had this gorgeous little face you just wanted to squidge, she was just so adorable.
"She was one of those people that from the day she was born, you just knew she was going to be beautiful. The pictures of her as a child are brilliant."