Amy has attended therapy sessions since the Seventh Grade and is described by Dylan to be a "neat freak" as she cleans out her purse regularly and always brushes her teeth after a meal. While Dylan dislikes Amy, Josh Rosen thinks of her to be "kind" and "classy." He has feelings for her, which Amy reciprocates. She also claims to be a fan of Josh's films.
When the entire school turns against Dylan after seeing Josh's documentary, Amy is the only one sympathetic to her and the two mend their friendship. Despite that Amy originally planned to attend prom with Asher as her date, she had wanted Josh to ask her, inadvertently causing Dylan to realize the sacrifices Josh had made for their friendship, as he had offered to stay home with her during prom festivities.
At the end of the book, Amy is dating Josh.
Portrayal in the Disney film
Amy is a musician who was Dylan's best friend in elementary school. She used to be friends with Dylan until she ditched her in the Sixth Grade. She plays in a band called Blue Tangerine. She is down-to-Earth, friendly and affectionate.