Leslie Mann on the Perks (and Drawbacks) of Acting Opposite Her Daughters in 'This Is 40' (Video)

Judd Apatow also reveals what 15-year-old Maude has inherited from her actress mother.

For Judd Apatow and Leslie Mann, the filming of This Is 40 served as a take your daughter(s) to work experience.

While the girls, Maude and Iris, first appeared as Mann's onscreen children in 2007's Knocked Up, their roles have expanded significantly for the 2012 "sort-of sequel," as it's been billed, with 15-year-old Maude apparently taking cues from her mother. (The sisters also starred in Apatow's 2009 dramedy Funny People.)

Apatow has previously said that he admires Mann's uncanny ability to draw humor from dramatic moments -- a talent that he believes their daughter has acquired.

"They play the truth of the moment, and if you play things completely real, then certain ridiculous aspects of people's way of fighting or communicating will pop out," Apatow told The Hollywood Reporter in a recent interview. "Leslie can just play the drama, and the comedy pops through. I don't even get why, but Maude can do it as well."

Mann said she felt very "lucky" to spend time with her daughters on set for 40, but playing mom to Emma Watson in The Bling Ring also had its (different) perks.

"With Maude and Iris, I just feel lucky that I get to be with them all day, but it's also hard, because I'm mom and I'm also working," said Mann. "So if they're having problems or they hurt themselves or they're fighting with each other, I have to deal with that and put out that fire and I have to work, so it's like double the amount of work. With Emma, I get to leave her and go back to my trailer and rest between shots."

The Apatow family, with Paul Rudd playing dad and Judd behind the camera, hit theaters Dec. 21 in This Is 40.

[Editor's Note: The reporter mistakenly identified Emma Roberts as Mann's co-star in The Bling Ring in the video above.]