If she was repeatedly hitting me or trying to seriously injure me with a weapon I would.
In 7th grade this girl slapped me because I said something she didn't like. I probably called her a name or something. After she slapped me I kept talking shit and she ran up to hit me again. I walked away and she chased me and started punching me in the face so I reached back and punched her in the face to get her off me. Everyone was giving me shit and I was like "this bitch punched me like 9 times." I think I was justified in putting that bitch in her place.