This is probably a bigger issue for the fighting systems that we train. We have an uncommon way to make a fist in comparison to other many other systems. One would think making a fist would be easy to learn but it often causes difficulty as it forces people to break the habit of how they originally made a fist. The other problem with the type of fist that female beginners have is that somehow the grip in such a way that it angles the bones in the knuckles instead of lining them up correctly. It takes about 3 - 6 months of reminding new students and eventually it goes away as it becomes natural and replaces the old habit. I'm always telling students to take their time with learning the techniques and to not try to rush the learning process. There's a difference between a gifted student that learns fast and a student trying to force the learning process.