She is devastated that she shot Charlotte, but she had every reason to believe someone from HER past was after her (she might have been a target when Curtis was shot, someone burned down her house and she had received serious threats.
When she talks to/about Valentin, she rightfully says she never would have shot first if he had let her know that Charlotte was the one who trashed her room.
I see a woman who is haunted by what she did. But I do thinks she has every right to be angry with Valentin.
Karen L.