Debbie Marshall is a bully and somewhat "popular girl" at Claire's high school. She has blonde hair, and green eyes, and her height seems to be average.
Debbie Marshall is portrayed by Dianna Agron who is well-known for her role as Quinn Fabray on Fox's television show, Glee.
Debbie Marshall is a cheerleader in the school which Claire attends and she is a bully as she teased and picked on Martha in gym class. When Claire stands up for Martha, Debbie challenges her to do a cheerleading stunt but Claire declines.
In the episode, The Line, Debbie continues to tease Claire and when cheerleading auditions are held, Claire tries out with two other girls but Debbie rejects all of them. Whilst Debbie is smearing a cupcake across someone's face, Claire and West plan a prank on her. After a late practice of Cheerleading Debbie is drunk from drinking some alcohol. Claire talks to her in attempt to join the cheerleading squad, but a mysterious flying man grabs her and drops her from way high above appearing to kill Claire. Debbie calls the police but Claire had disappeared when they arrived. After the police find the bottle of alcohol Debbie had drank, she gets suspended from the cheerleading squad.