Does not matter a bit. Unless you've clearly seen that she started the assault, you default to protecting the woman. Even if you saw her start it, you don't allow her to be destroyed, deserving or not. You step in after she got as good as she gave. But then, I'm old, raised in the old way. Your mileage may vary.
I’m into my 5th decade. The times have changed. Drastically. For me personally, if I knew she was a lib I would have to consider this as a person that supports destroying the normal way of life I recognize. They created this mess by fostering and coddling every seditious and perverted idea that led to their moment of truth. It would be tempting to leave them to their fate, but you are right. I’d still try to land a few haymakers to aid her. ;-)