Trivia: The little pesky sister, Dolores Rebchuck, does the voice for Bobby Hill on King of the Hill.
Trivia: The character of Brad is played by Matt Lattanzi, the future husband of Grease star Olivia Newton-John.
Trivia: Adrian Zmed, who plays Johnny Nogerelli in this film, actually played Danny Zuko in 'Grease' on Broadway.
Trivia: Alison Price, who plays the Pink Lady Rhonda Ritter, is the daughter of Patricia Birch, the film's director.
Trivia: Watch closely during the opening number, when the three guys steal basketballs from the other students, the guy in the middle knees his target in the groin. It was reported that it was not a scripted move and a fight ensued between the two men after 'cut' was called.
Answer: I don't think it is ever mentioned as to who played the two nuns. I think they're just extras.