Ginny's really not helping her situation if she wants to get in with Harry. Angering Hermione is the fastest way to push him away.
I know that we probably won't be able to get it, but I'd really like for Luna to join Harry's Coven. I can't explain it, but I think she'd be a very valuable addition, and if Hermione hadn't already been the HBIC, I'd say Luna might make a good one.
Um, I think you might want to have Emma (Coven) move on since you've name Hermione's mom Emma. It might be a good idea to avoid having girls in the coven with the same names as girls in the extended family, since it can get confusing. When Emma walked in, I didn't know which Emma it was until Hermione said mother, and if you've got both Emmas in a discussion, it could get really confusing distinguishing them for both writer and reader later. Trust me, it's an almost unavoidable mistake.
I like your Luna, she's an interesting one for sure.