The actress, 43, nailed boho chic in a white slip dress under a brown knitted jumper, teamed with a pair of chunky brown leather knee-high boots.

Actress Sienna, 43, looked effortlessly chic as she arrived at the celebrations wearing a white slip dress under a brown ...

Sienna Miller's daughter Marlowe, 12, looks all grown up as they pose together in a rare appearance. The actress shares her ...

Sienna's boyfriend, Oli Green, was also in attendance. Sienna Miller just stepped out for the cutest mother-daughter date with Marlowe Sturridge, whom she shares with ex-husband Tom Sturridge ...

Sienna Miller just stepped out for the cutest mother-daughter date with Marlowe Sturridge, whom she shares with ex-husband Tom Sturridge—and brought along her boyfriend, Oli Green. The trio ...

Dave Benett/Getty Sienna Miller, Marlowe and boyfriend Oli Green Related: Sienna Miller Says She Adopted a Bunny She Met on the Horizon Set for Her Daughter (Exclusive) Speaking with PEOPLE in June ...

Sienna Miller just stepped out for the cutest mother-daughter date with Marlowe Sturridge, whom she shares with ex-husband Tom Sturridge—and brought along her boyfriend, Oli Green. The trio, who were ...

There’s no denying that Sienna Miller has strong genes. On April 1, Miller and her look-alike daughter, Marlowe, 12, made an appearance at a bridal event held at the Four Seasons Tower Bridge in ...

Sienna Miller's daughter looks all grown up ... Another snap shows Marlowe, Miller and the star's 28-year-old boyfriend Oli Green, who can be seen putting an arm around Miller.