London, Jan 5 (IANS): Actress Sienna Miller says that becoming a mother for the first time "changed everything" for her.

Miller gave birth to daughter Marlowe, her first child with fiance Tom Sturridge, back in the summer of 2012.

"I think having a baby really changed everything, if I'm honest. I think that's where it began. The stakes are higher. You have someone that you want to be proud of you eventually.

"You're aware of your own mortality. For me, as soon as I had a baby I had a vision of my life - and what was left of it," she said in an interview to The Observer magazine, reports femalefirst.co.uk.

Miller believes that motherhood has also changed her professionally as she believes that she is taken more seriously as an actress now that she has become a mom.

"People who read the negative things (about me), the people who need persuading, are probably ignorant enough to assume, 'Well she's got a kid so she's serious now'. Which, of course, isn't the case.

"I'm still whoever I was. Maybe more mature, but the same. So amongst that ignorant, ridiculous area of my industry, I'm sure opinions of me have changed because I'm a mother now," she added.

Miller will be back on the big screen later this month as she stars alongside Steve Carell, Channing Tatum, and Mark Ruffalo in the already critically acclaimed "Foxcatcher". The film is releasing Jan 9.