Hi. Ok, I'm new here. You would think that after all these years of being an avid book reader I would have found this site before now. So, on to my post. I'm not sure if this is the right place for it but seing as you are discussing childrens books I thought I would give it a shot. There is this book that I read when I was a kid, I don't remember the name. Anyway, there was this girl who moved to a new house and school. A plain Jane kind of girl who wanted to be beautiful and popular. Surprise surprise, up in her room there was a vampire that would visit her. She told him that she wanted to be beautiful so he gave her beauty. The catch was that the beauty he gave her, he took from someone else, namely the prettiest and most popular girl in school. He gave her several things over the course of the book and I think she defeated him by giving back all the gifts he had given her.
I'm not getting my hopes up that anyone here knows what I'm talking about but I am hoping (with fingers crossed) that my limited description will ring a bell or two.