The Three-Handed Man Pushes Dumbledore

A thief, a con artist, and a little hoodlum enter Hogwarts. The person she hates most is Dumbledore. He gave her a scolding. When did she start liking him? I admit, this is basically, "Tom, you're starved for love, Dumbledore doesn't like you, so you turn into dark fertilizer." But I just have to write a story where he starts from an even lower point. No turning evil! He'll grow into a fine young man! And fall in love! I'm still undecided whether the protagonist is male or female...