Ms. G made me sick

What would be the point in expressing hatred for a fictional character? If anything it say a lot about Eva Green being such an excellent actress, being able to provoke such strong reactions.

i agree with OP. and if you were one of her victims, you wouldnt think her story is tragic or sympathize with her. and these kind of people exist. their past or mental status doesnt reduce the damage they cause.

Good for you and the reaction to you, unfortunately, is the norm. After being around for a long time, I learned long ago that most people have no real insight to others and their actions. For those of us who pick up on others very quickly, we can come across as "ice queens" because we aren't falling all over ourselves over someone else's BS. People feel such an overwhelming need to belong. Their pack mentality.

Did you also notice how ugly she gradually became as her inner self was revealed more and more?

It was very upsetting to see that everything was covered,

After reading this entire thread I'd like to point out why I detested Ms G. Besides the fact that she was an abuser- she MURDERED a child. And got away with it.

I went a single sex British school (not a old-fashioned boarding school, but quite an institution nonetheless), and I recognised the characters/forces at play, although none were so extreme, and no one got molested or murdered, to my knowledge, but some of the dynamics were similar.

It was a stupidly intense, rarified, and unnatural atmosphere... vieing for the 'cool' (or simply male) teachers' attention, the over-competitiveness that is cruel to force on teenaged girls (IMO), the cliques, the prefects, the pets and the dweebs. I even remember the anticipation of having a 'new' student join the class, and how it could disrupt the fragile ecosystem. It was a good education, but bad for socialisation. It made everyone a bit weird.

Well, I've never met anyone like Miss G, so maybe that's why my opinion of her is less negative. As some have already mentioned, she's a troubled and complex character, and a few scenes at the movie hint towards mental illness and trauma (mainly the one at the store, and her in the bedroom towards the end of the movie).
As I see it, she could have redeemed herself if she hadn't let Fiamma die.

Eva Green was amazing, by the way.

She has a very complex personality, and she is herself a victim of the institutionalized setting. The film clearly explores some dramatic impact a single-sex boarding school like this can have on a person. For Miss G, she has lost the ability to deal with the real world. She has problems communicating with people outside, and she is still going by the rules at school(You can see her counting the objects on that nighttable towards the end of the film)("You can have five personal objects on display"). She dreams of going outside like mad but she can't, so she makes up these stories for herself. She is obsessed with Fiamma because she wants to be her.

Yes,its a very unpleasant character but i can see a reason why she is like this. I hate her for what she did to Fiamma but i cant help but feel a bit sorry for her too.