Reese Witherspoon says there aren't enough "great movies" for her to do more than one a year.
The 'How Do You Know' star tries to strike a steady balance between the films she makes and her two children - Ava, 11, and seven-year-old Deacon, with former husband Ryan Phillippe - so tries to restrict the number of roles she takes on.
She said: "I try not to do more than one movie a year, just because there's not that many great movies to do and also it's hard for me to be away from my children for too long.
"It's a big commitment, and then you have to sell the film, too. After that, I don't have a lot of rules. I try not to put too much restriction on it because you never know what's going to come into your life."
Reese, 34, also claimed it is important for all of Hollywood's A-list actresses to support each other.
She added to Total Film: "I think it's important that we all support each other. And the better one woman does, the better all women do.
"The better Sarah Jessica Parker's movie opens, the better it is for Julia Roberts and myself and all the girls coming up. It's important that we all support each other."