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making a fist would be easy to learn but it often causes difficulty as it forces people to break the habit of how they originally made a fist.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.Then we start teaching them things like how to make a fist correctly.
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.