Why don't you sing "Toucha-toucha-toucha me" from Rocky horror? It's comedic and need some technical skills to make it sound good. Or maybe you're not allowed to use songs from the show, because of some whatever reason the director have?
But it all depends on what role you are auditioning for. Is she sweet, naive, obnoxious, tomboy? Are her vocals crazy difficult or purely comedic, or both?