I'm sorry to be picky, because it is a great idea, but please. Mum, not mom. Please! Otherwise, this is wonderful - very different (ha). Ginny seems to be almost fading away at the beginning, which reinforces the idea that house identity is so important to the kids at Hogwarts, that they define themselves by that one character trait when really they're other things, and I think you conveyed that in "the Slytherins think it's funny and it upsets Ron." Not having that identity makes it almost shameful.

Ramble ramble ramble, sorry. I do like it, but that one thing got me - I am a terrible Brit-picker.