Ally—the protagonist and narrator of Fish in a Tree—is an intelligent, witty, and creative middle-school student. She has strong math skills—strengthened by her family’s interest in antique currency—and impressive artistic skills. Ally has a fascination with Alice's Adventures in Wonderland, spurred by her recently deceased grandfather, with whom she was very close. Part of her fascination with the book stems from her identification with Alice. As Ally phrases it: “a book about living in a world where nothing makes sense made perfect sense to me” (19).

Ally struggles with all reading and writing-related tasks at school. She goes to great lengths to avoid these tasks, and her strategies include humorous deflection, feigned sickness (escaping to the nurse’s office), and misbehavior (which forces the teacher to send her to the principal’s office). Her struggles originate from dyslexia, a learning difference which often makes some letters appear backward and some appear to float on the page. Though Ally’s teachers are supportive, they often mistakenly believe—because of her strong intelligence—that her struggles with reading and writing can be fixed if she simply applies herself. This misconception carries over from school to school, as Ally moves around frequently, following her father’s career with the military.