Walt Disney Studios previously confirmed the kids' 4-year-old sister Vivienne will play Elle Fanning's Princess Aurora character at a younger age.
"They have smaller parts," a source told UsMagazine.com about Pax, 8, and Zahara, 7, who won't have speaking roles in the movie. "[Six-year-old] Shiloh was supposed to be in it, too, but she was bored and not in the mood during the day her part was supposed to happen, so she ended up not being in the film."
Jolie plays the titular villain in the re-imagining of the classic fairy tale "Sleeping Beauty," which is set for a March 2014 release.
'Maze Runner' brings in $11.3M Friday
Dakota Fanning says her mother is no stage mom