I'm stuck between 2 of my most important values:
1) don't hit women. not a lot of explanation needed
2) if women want to be treated as equals, they should be. If a person, male or female, takes the first swing, anything after that can be self defense and you deserve whatever ass whooping you receive. if you're not willing to risk that, don't swing first.
IMO you never hit women, but she clearly swings first and should have no legal ground to stand on.