This is great! Your writing style is reall quite different and interesting, the story flows well, and I don't think theres any chance of Ava turning out to be a Mary-Sue *holds out wooden cross to ward away the Mary-Sue zombies*
Seriously, it's so hard to find some good OC storys. There all about these beautiful girls that have every guy falling for them and never get defeated. T_T
Would you be really, really kind, and check out my story 'Who I Am?' I'd be really pleased if you could, I'd like to get some critique from all the writers I think are god. It's quite long though, I'll warn you now XD