Who is Melony from The Cider House Rules and what is their importance?

Melony is one of the orphans who lives at St. Cloud's. Like Homer, Melony never gets adopted. It is Melony who introduces Homer to sex for the first time, and she makes him promise that he will never leave her at the orphanage. When Homer runs off with Candy and Wally, Melony runs away and spends most of the rest of her life trying to track Homer down.