Just a couple of things to add...I heard a guest on a radio talk show a few days talking about what she teaches in her classes for women, and the biggest point she made about reacting is that even though you are taken off guardm you can recover quickly if you remember to breathe. She asks a lot of her participants what they'd do if someone attacked them and too many say things like "Oh, I'd probably panic or faint or lose my breath until it's too late." Then she asks them what they'd do if someone tried to take their child. Their response is typically along the lines of "I'd kill, maim, break, mangle, etc him." So why not react that way if someone tries to take your kid's mom, being you? I thought that was a pretty good way to put things into perspective and help bring out the fight or flight mechanism in the women.
The other thing is, don't be afraid of the punches being too weak. This is one thing that I've seen taught a lot that I disagree with. I've seen classes do push-ups to help with punching muscles, etc., but that doesn't necessarily help. I believe that the secret to a good punch is speed, not power. Power is for pushing, shoving, lifting, etc, but speed is for damage. My teacher and I came up a with a good analogy for this...Have you ever hit a baseball or golf ball or softball, etc, and it went forever, but you really didn't feel like you got all of it? Thought to yourself "Man, if I had hit that thing as hard as I could have, I probably would have set a record. I really wasn't trying on that one and it went pretty far." Well, the reason is that when muscles are tight, you are more pushing the ball than you are swinging at it because tight muscles create tension and resistance along the bones, other muscles, etc, and actually can serve to slow down the punch. A good, loose punch will come out noticably faster than a tense one, so in a way, I might rather take a punch from Arnold Schwarzenegger than from a 12-year-old girl. Keep loose, and just sling your fist out there. To practice, throw one as tense as you can, then throw one easy and see which hurts more. It takes a bit of practice to see what I'm talking about, but try it on pads, heavy bags, each other's arms, whatever, and after a few tries, you should notice a difference.