BETTY: In this film, you have Kristen Stewart playing your daughter. Do you like working with children on set?
JODIE: "I love working with kids. I always have. She's a great. We hung out. That's what we did. Never talked about the movie. Never talked about the characters. In between takes we'd talk about bands and stuff like that. I was lucky to be stuck with her. Really young actors work the same way that I work. That is they don't belabor it. All of the intellectual stuff [and research] they do ahead of time. And when it comes time to perform and somebody says action, you just do it. And then you talk about other stuff."
David Fincher on Kristen:
"We cast Kristen Stewart [as the young girl], and she reminded me of a young Jodie Foster. She has that sort of great droll sense of humor. When Nicole [Kidman] hurt herself, we thought we were going to shut the movie down and get an insurance claim. A [producer] told me that Jodie’s movie fell apart, and it was like let’s send her the script!"
source musicolog.com via allkristenstewart