I agree with cptcave. It kind of feels like those people who leave cults and have to go through deprogramming before they can function in society again. She seemed to have snapped and then decided to kill everyone who was involved with Daniel’s death. Then she just couldn’t stop being evil – then she started killing people (and things) that weren’t involved with Daniel’s death in order to continue being evil (her horse, her father) and I don’t think she even understand WHY she wanted to be evil or even IF she wanted to be evil at that point. It’s like she needed to go through deprogramming.
BUT – I do feel sorry for her for ONE reason, I think she COULD have been saved except for the fact that I think she did kill her mother and according to Rumple, if you kill someone evil you become as evil as they are. I have the feeling she killed her mother not understanding that. So if that is true, I do feel sorry for her because I don’t think she necessarily has control over her actions the way a normal person would. And I think Regina may be one of the reasons that Rumple wants to do away with magic – not because they are enemies, but because he sees her as a victim as well, even if he doesn’t admit it to her.