Miss Collins was a two-face…

(Spoilers…)

Hear me out. So I know the narrative presents her as sweet and well-intentioned and caring about Carrie’s well-being. But pay closer attention, she hides an alter-ego…

Early in the movie after the girls were horrible bullies to Carrie in the locker room, Miss Collins is talking to the principal, and she says “See the thing is, I kinda knew how they felt. I mean part of me wanted to grab her and shake her too. It was just her period for Christ’s sake.”

Miss Collins probably was a bully in high school just like the girls, and still had a bully side of her just like that piece of dialogue reveals. She’s certainly physically pretty so surely she was popular in high school. So she can empathize and relate to these girls.

Then her alter-ego rears its ugly head again when she’s interrogating Tommy and Sue. She says to Tommy “Look Tommy, don’t you think you’re gonna look just a little bit ridiculous when you walk into the prom with Carrie White?”

All of this leads up to the moment she can’t help herself and joins the crowd in laughing at Carrie at the prom. I always hear people say ‘There’s no way Miss Collins was actually laughing at Carrie, Carrie must’ve hallucinated that.’ But the thing is, the moment where Carrie slams the doors shut to begin her massacre, we see the whole crowd of students in the shot actually laughing as some start to walk out & have the door slammed on them.