A suggestion, someone said to get off when she kicks out when undersaddle and then lunge her. I would not get off, and instead just really work her while you are on her to let her know it is not acceptable behavior. By getting off, even though she is getting worked, she is going to associate "oh if I kick out then my rider gets off." So if you feel you have the experience to sit it out that would be the best thing.
What is your level of experience? I am getting the feeling that you are somewhat inexperienced. If you have the option of giving the mare back and finding something that is more suited to your needs I would do that, just for your own safety. Horses that kick out that much at you are dangerous, and can become more dangerous if you do not possess the necessary experience and confidence in handling such situations. Not to mention you will have a lot more fun with a horse you can trust 100%! If you really like the mare, I would have her checked out by the vet to make sure she is not in pain, and be sure and find a saddle that fits her. Ill fitting saddles can cause a horse to behave in the manner she is portraying.
Something else you can do with her to help est. Dominance, in a controlled setting is to do in-hand ground work. Get a dressage whip (they are longer then crops, so you can be further from her hind end!) and stand at her head (have her in a halter and lead rope) ask her to yield her hindquarters by touching her softly with the whip, if she does not move off the pressure start tapping, increase the pressure of the tapping until she moves (reward for the slightest try at first, reward is to stop tapping). Then work on turning on the hindquarter (yield the forehand), work on side passing or leg yielding. By doing these exercises in hand you will be able to develop control of her body parts. Then when you get on her back you will be able to ask for the same exercises to help get her really listening and paying attention to you. In hand you can also work on backing, halting, walking off immediately with you, trotting in hand. There is so much work you can do in hand that is much safer than turning a horse, that likes to kick at you, loose in a round pen (this will allow her much more access to kick at you).
Last edited by SaddleUp158; 01-16-2009 at 12:56 AM.