Actress Rosario Dawson has reportedly adopted a 12-year-old girl.

The Sin City star became a mum to the girl in October (14), according to the New York Post.

Dawson, who was adopted by her stepfather as a one year old, has spoken about her desire to become a mum in the past.

In 2008, she told Latina Magazine, "I always wanted to adopt kids because my dad adopted me. That idea has stayed in the back of my head, but lately, I've been thinking about it more.

"My mother and grandmother are extraordinary women, and they're getting older. It struck me recently that one day I might be sitting around with my children, going, 'Your grandma was an amazing woman; I really wish you could've known her'.

"That makes me sad because it would be a waste to not have these people know each other. Whatever time I have, I want it."

Dawson is currently single. She split from director Danny Boyle in 2013.

A representative for the actress had yet to respond to requests for a comment as Wenn went to press.