That's interesting... I imagine it must have something to do with the difference in center of gravity between males and females, and a woman typically having wider hips and more weight around that area.
Coordinating the movements to the breath is really helpful, and it was through my other yoga studies that I really learned to focus on this. When you focus on the breath, you can often forget about the other issues going on to inhibit your progress.
Another thing I do, and I'm not sure whether this is good or not, is, instead of counting to 21, I count to 7, 3 times. Psychologically, this really seems to help.