I'm not so sure she's an introvert. She's always giving lessons to peoples and trying to help them, even when nobody have ask her anything. That's sounds more ENFJ to me.Anyway, Lisa Simpson seems to be the prototypical INFJ.
Wesley Wyndam-Pryce from BTVS and Angel, the Count Dooku from Star Wars, Scar from The Lion King, Paul Atreides from Dune, James Wilson from House M.D and the Dctor Zhivago from Doctor Zhivago are famous examples of fictionals INFJs. Oh, and Amélie, obviously!