The pair starred together in the 2002 David Fincher thriller Panic Room, where they played a mother and daughter terrorized by a home invasion.
Foster appeared at this year's San Diego Comic-Con, where she took part in a special panel for her upcoming film Elysium.
It was the actress's first time attending the popular convention, and she admitted that she should have asked for tips from Stewart, who has attended the event five times.
"[Kristen] really should've given me some tips," Foster told Access Hollywood. "She's doing great. I just saw Snow White and the Huntsman, which I thought was extraordinary and I thought she was absolutely brilliant in."
Stewart, who stars in Breaking Dawn Part 2 later this year, was recently named the highest paid actress in Hollywood in Forbes magazine.
"I'm proud of her," Foster added. "I feel like she's my daughter too!"
The Silence of the Lambs actress stars alongside Matt Damon and Sharlto Copley in Elysium, helmed by District 9 director Neil Blomkapm.
Elysium is scheduled for release on March 1, 2013 in the US and the UK.