Sienna Miller's fashion designer sister Savannah, 43, marries aristocrat James Whewell

Sienna Miller cuts a stylish figure in a checked coat and knee high boots in New York

Jessica Chastain Kicks Off The Holidays With Michaela Coel & Sienna Miller at Moet & Chandon's Holiday Party

Sienna Miller serves up legs and cleavage in a VERY sexy LBD at Moet and Chandon event in NYC