I think you lose your right to be called a victim when you make someone else a victim.
Even if other parties were involved and didn't act when perhaps they should have, ultimately, she was the one who killed not one, but two children. She and only she is to blame for that. Yes there could be others to blame for the fact that it got to that point, but she is the one who ended those lives and she should be held accountable.
I have every sympathy for her ex, for her family, and mostly for her children, but I have no sympathy for her. I think when you take someone else's life you lose the right to sympathy.