Flute Girl has long brown hair, glasses with magenta rims, and braces on her top teeth which give her a lisp. She wears a long sleeve white shirt underneath a green sweater vest with a black eight note on the front. In addition, she wears a dark red violet skirt, white socks, and black dress shoes.
When she's involved with the marching band, she'll wear the normal band uniform. Her instrument is a flute that she calls Princess Tootie.
Her normal appearance when she is stanked by the Sorcerer is a blue tyrannosaurus-like monster with a large mouth. In "Lucius O'Thunderpunch", she tries to chomp the Ninja, but he stops her by breaking free and knocking her out.
Flute Girl does well in school, and gets easily annoyed with anyone who slacks off or comes off as an idiot, especially Randy and Howard. For example, in "McFists of Fury", she couldn't believe they didn't know who Brawn Brickwall was. She also is frustrated with people who don't listen to her, like Bucky doing a triangle "solo" during "Got Stank" and singing instead of buying her a McFist Tunes gift card that she wanted in "Silent Punch, Deadly Punch". She usually follows the rules whether she likes it or not, having no choice but follow Howard to Mt. Chuck because of the five-foot rule. However, she is nice, comforting Bucky about being tricked to go up the volcano in "Monster Dump", and often thanking the Ninja whenever he saves her.