It sounds like the red belt is either jealous of you or power hungry, either way I would avoid her if possible. If you truely are kicking to hard then you need to learn control. Have any of the other persons you have sparred complained to you about going at it to hard? Have you asked any of them if they thought you were too aggressive? If you do not feel comfortable training with the women any longer then ask to be partnered with a male counter part. I have met many women that can go toe to toe with men and they're proud of it. When I used to teach, I made it a point to partner men and women together. Most attacks on women are from men so you have to know how to defend yourself against men. If they insist on just placing you with women then I would look for a new school. I have taught many different types of arts and there is always someone that is uncomfortable sparring with or even just training with the opposite sex. This is always best to listen to what the student wants and try to accomadate them, but sooner or later, they will have to train with the opposite sex. Oh by the way, most men won't admit that your hitting them to hard....LOL
Kik
Kik