My own mother turned a blind eye to abuse and told me to shut up about it as an adult. She was abused herself as a child (not to the same extent) and had myriad 'reasons' for her failure as parent. I don't forgive her. Her duty as a parent was to protect me. She failed. While I wouldn't like to see her jailed for it, I would not absolve her of any responsibility.
cailin, that's completely understandable. If my mother had stood by while my father abused me, I would have a very hard time forgiving her, even if I later understood that she was also a victim of abuse.
I'm not arguing that people should feel sympathy for this woman, or that she had no responsibility or duty of care towards her daughters. I am stating that it is an outrage to jail women for violence that men commit. Men are responsible for male violence. Not women, no matter how much they may fail as mothers.