As many reviewers have stated, the main character Nadine is more then just going through growing pains. She shows signs of deeper emotional problems that go way beyond losing her father.
Almost all of Nadine's problems are brought on by her own actions. And when one is unaware that they are the problem, it will continue. Unfortunately here, she does a complete 180, over the coarse of a night. I didn't like that. But maybe time constraints prohibited from telling this gradually.
One of the strongest disagreements I've seen in reviews has been over her life long friend. To me this might have been the ONLY thing Nadine was justified at feeling betrayed. Key is lifelong friend. Who we see in one scene is actually targeting her brother. Then in the next she's found in bed with him. Then in the next she's all mushy mushy with a girl who wouldn't talk to her before. So yes Nadine, giving her an ultimatum was probably not the right next move, but never speaking to her again would have been. You just don't do that to friends.
I found Woody to be a great choice in a supporting but important role as a very grounding and level headed teacher.
Hailee Steinfeld's performance once again shows she's a force now, and in the future.
Though the ending was to quick at resolve, it was definitely worth a watch
Review of The Edge of Seventeen
