As previously reported, some of Jolie and Brad Pitt's kids — Pax, 12, Zahara, 11, Shiloh, 9, and Knox, 7 — voice characters in the animated movie. (Brangelina are also parents to Maddox, 14, and Vivienne, 7.)
"[It] was so much fun. I think what was so sweet about it was that they took it very seriously," Jolie, 40, told Radford. "They came in and said, 'I don't know if I could do this. I'm not sure if I can do this.' And to talk them through it — it was simple little things — but they really took it seriously as a job and getting it right and not doing a bad job." (Jack Black's son Sam, 9, is also part of the cast.)
When asked if her children would ever want to act for a living, Jolie quipped: "I hope not! We've always said if they want to be actors I hope they do something [on the side in addition to being] actors."
Jolie and Black, 46, have voiced Tigress and Po since 2008's Kung Fu Panda. The By the Sea director, in particular, is grateful to be a part of the franchise.
"I think anything that comes from such a good place is very special. And the intention of this is to do something for children," she said. "It's relatable for everybody, but it is for children and it has beautiful messages of embracing who you are, being a family, loyalty, understanding all types of family."
Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!