It would depend on his/her physique. If they were big and burly, I probably would just try to run/call for help/police. (or try to use my words to persuade, or trick the perp into some point in which I had better chance to run or something)
But, if they were average to small, I would definitely fight back.
Right between the legs hurts a LOT, male or female (the bone hurts), and can slow them down while running for help.
I say it depends, because I'm not very fit and I have a bit of a small stature. (I'm not fat, I just don't really use my muscles)
If I knew how to turn my opponent's weight/strength against them without really fighting, (Like Aang), then I would.
But I don't, so I can only take on what I think I can handle.
Now don't get me wrong, it's NOT that I go out looking for fights, but if I ever were in a situation where fighting was one of the only options to resolve an issue, then I would at least use what I DO know to get the upper hand and get out of the situation the best way I can.