United Kingdom, July 13 -- Sienna Miller inspired her sister to have another baby.

Savannah Miller, 47, opened up about her "complicated" fertility journey in an interview with Vogue, as she said Sienna's three kids - Marlowe, 13, a two-year-old and a newborn - made her realise she could "handle" another tot.

Savannah, who is already mum to Moses, 21, Lyra, 18, and Bali, 14, from her first marriage, explained: "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, ...