As the story begins, Miss Desjardin secretly feels the same disgust everyone at Ewen High School feels for Carrie White. However, when she witnesses Carrie being humiliated by the other girls in the locker room after gym class for her hysterical reaction at her first period, she realizes that it is the girl’s first menstruation and that Carrie is oblivious to what is happening to her, and feels sorry for her along with confusion as to why her mother never informed her on it. Desjardin wants to punish the girls who taunted Carrie by having them suspended for three days and banned from the upcoming senior prom, but the principal settles on a lesser punishment: a week of boot-camp style detention in the gym. In Desjardin's view, the only reason the administrators didn't go along with her proposed punishment is that they are all men, and thus didn't really understand just how nasty the girls' behavior had been. Lead bully Christine “Chris” Hargensen defiantly skips the detention and thus is banned from attending the prom. The principal reprimands Miss Desjardin for cursing at Chris, but stands by her when Chris' father threatens to sue unless Chris is allowed to attend the prom, unless Desjardin is fired from her job. Meanwhile, Sue Snell, another girl who participated in the locker room tormentation of Carrie, feels remorse for her actions and thus asks her boyfriend, Tommy Ross, to take Carrie to the prom to make amends. At the prom, Desjardin talks with Carrie about her own prom night and later, congratulates her for being voted Prom Queen. As revenge for being banned from prom, Chris has secretly rigged a cord connected to two buckets hidden above the stage where Carrie and Tommy will sit on the thrones. When Chris pulls the cord, both of the buckets tip over, drenching them both with pigs' blood. Desjardin reflexively responds to the prank by laughing. However, she later tries to help Carrie, who pushes her aside with her telekinesis, because she telepathically sees that deep down Miss Desjardin is still laughing at her. Once outside, Carrie uses her telekinetic abilities to wreak havoc on the school with the intention of killing everyone in the gymnasium. She then destroys the entire town on the way home. Desjardin is one of the few survivors of the "Black Prom". Two weeks after the disaster, and with 440 people dead, Desjardin retires from teaching, saying she is consumed with guilt for not doing more to help Carrie and that she would rather commit suicide than ever teach again. She also implies in her resignation letter that she feels guilty for having laughed at Carrie like everyone else instead of helping her or comforting her.
Adaptations
1976 film
In the 1976 film version of the novel, the character is named Miss Collins and portrayed by Betty Buckley. Unlike the character in the book, Miss Collins does not first experience revulsion toward Carrie, as she is suggesting in the beginning that the students pass the ball to Carrie in their volleyball game. After the locker room incident, she also punishes the girls, and when Chris argues with her during detention, Miss Collins slaps her and makes the infuriated Chris skip detention, thus being banned from prom. She becomes more sympathetic and attempts to help Carrie overcome her awkwardness when she realized Tommy asked her to prom, and reprimanded him and Sue for trying to do so. After Carrie uses her powers to wreak havoc on the school, Miss Collins is seen trying to move the unconscious Tommy, along with another teacher and three students. Carrie pulls her across the floor and pins her against the wall. Carrie then smashes a basketball rafter into her, killing her.
2002 film
In the 2002 version, Rita "Desjarden" is portrayed by Rena Sofer. After finding out that Chris and her top henchwoman, Tina Blake, compounded Carrie's locker-room humiliation by vandalizing her locker and filling it with tampons, an angry Desjarden hurls a bag full of tampons at them the next day. She then announces that they've been sentenced to a week of detention, telling that skipping the punishment would result in three days' suspension and banishment from the prom. Chris, refusing to take her punishment, storms out. The principal reprimands Desjarden for this, but stands by her when Chris's father threatens with a lawsuit unless Desjarden is fired. At the prom, she talks to Carrie about her own prom date. In this version, she says her date carried a fake gun to imitate James Bond but he ended up arrested. As a result, she remained alone at the prom until her father came and took her home. She also tells Carrie that things change, and not always for the best: the pretty, popular girls will be fat, cute boys will be bald, and the miserable ones might have a happy life. When Carrie begins destroying the gym telekinetically, in revenge for being drenched in pigs' blood, Miss Desjarden sends two students to carry the dead Tommy and leads an escape through an air vent. She is the last one to leave the gym and is nearly electrocuted, but survives and reports the events to Detective John Mulcahey, revealing her conclusion that Carrie must have been behind the destruction.
2013 film
In the 2013 version, Desjardin is played by Judy Greer. As in previous film portrayals, she sympathizes with Carrie and tries to help her. Desjardin is spared from Carrie's wrath during the prom as she was the only one who wasn't laughing at Carrie and tried to help clean her up. She uses her telekinesis to throw Desjardin out of the way of falling electrical wires. Desjardin is last seen with her arm in a sling, telling Sue that Tommy is dead.
Performers
Betty Buckley
Darlene Love
Rena Sofer
Carmen Cusack
Judy Greer
Ashleigh Murray
Musical
In Carrie: The Musical, Miss Desjardin becomes Miss Gardner, a composite of the gym teacher and the principal. She opens the show with the song "In" where she orders the girl PE students to "Work, work, work, work!" After the "Shower Scene" Miss Gardner becomes much more sympathetic toward Carrie and even sings "Unsuspecting Hearts" with her to get her to accept Tommy's prom invitation. Miss Gardner was a chaperone at the prom, and died in Carrie's onslaught. She was portrayed by Darlene Love in the Stratford-on-Avon and Broadway production of the musical. In the 2012 revival, she was portrayed by Carmen Cusack.
Other media
The television seriesRiverdale, featured an episode based on the musical, "", with series star Ashleigh Murray, who played Josie McCoy as Gardner.