Tom Sturridge and Sienna Miller

Tom Sturridge and Sienna Miller

Sienna Miller says motherhood has given her "incredible perspective."

The 32-year-old actress realised that "life is really short" after welcoming her 20-month-old daughter Marlow, with her fiancée Tom Sturridge, into the world in July 2012, and becoming a parent has inspired her to approach her career differently.

The 'Foxcatcher' star told the April issue of Nylon magazine: "Life is really short. A lot of what we do is a reaction to what people think you're supposed to do. 'Have a kid by 30. Move in, but live together for at least this amount of time.' All of those rules I want to rebel against."

She added: "In the past I was always drawn to the roles, and was often really exploring characters, but then the final result was not what it was supposed to be. My modus operandi after I had the baby was to work with great people, no matter the capacity, even if I had a smaller part."

The blonde beauty previously credited her daughter for helping her to enjoy a more settled lifestyle and become calmer.

She said: "My twenties were a bit crazy. I spent those years working and being repeatedly persecuted by the media. Nowadays, I can be the woman I truly am, more calm, and freer too. I turned 30 and I suddenly had much less energy!"