I like this, it's well written and seems to have a good storyline so far but I'm a little confused about the whole memory deal. Like how she could just forget everyone. I feel like seven years isn't that long of a time, especially to forget someone she spent so much time with. Also, you mentioned that she knew the girls from 8 years ago, so it seems like she knew them for less time then Gavin and yet she remembered them and not him. Maybe that was a typo or maybe you'll explain it later on (like she's suppressed her memories), but it does seem a tad unrealistic right now.

Does she have amnesia?

Great first chapter, can't wait to read the rest :)