Miss Collins is one of the first characters to show kindness towards Carrie by prompting the other girls to pass the ball to her. During the shower scene where Carrie was mistreated, the light bulb bursts (which got caused/broken by Carrie with her powers), while she tended her.
Later, she goes with Carrie to the principal and explains what happened. The principal gives the girls a week's detention at her convenience or refusal of their prom tickets and three days suspension.
Miss Collins tells the girls how upset and angry she is with them. She makes them all do a merciless, week-long, boot camp-style detention to serve as a punishment.
When Chris Hargensen refuses, Miss Collins slaps and fights/argues with her and kicks her out of prom. Later on, Miss Collins sees an upset Carrie and asks her what's wrong and tells her how pretty she is and raises her hopes of finding someone. She finds Sue distrustful about wanting Carrie at prom and tells them off, warning them not to hurt her.
At prom, Miss Collins shares her prom story with Carrie and the two of them hug. She is later seen at the coronation of the Prom King and Queen.
When Miss Collins spots Sue, who tries to warn her about the bucket and kicks her out of the gym. When the blood is poured, she starts to cry.
When Carrie sees everyone laughing at her, she sees Miss Collins laughing and saying, "Trust me Carrie, you can trust me". As the massacre starts, Miss Collins can be seen trying to revive Tommy with Cora and a few others. She can also be seen grabbing Cora's ears trying to see if she had anything to do with the prank Chris pulled. Miss Collins and others try to carry Tommy and find help, but Carrie's telekinesis intercepts the crowd and pins Miss Collins to the side as Carrie kills her by slicing her in half with a falling basketball goal post.