Needs a bit of a content warning for bullying, especially in a school context - glad Sam and I didn't watch it together. It has some similarities to Dexter, in that she becomes a killer, but only wants to kill people where she really thinks the world would be better off without them. It's been renewed for a second season, though it's a little hard to see how they'll maintain any sympathy for the character now. It can be hard to keep a show compelling when you want the protagonist to fail, though Breaking Bad managed it.