1st G4life, your female student, probably did not break the pistols, I don't know her stature, but light people may not back up a semi auto, and limp wrist which causes failures to feed, 2nd, the course may have been too much to chew in one or two days. When you have a student that is lacking, that is when, as an instructor, to take a step back and work with that individual. Watch their motions and see what they are doing wrong, don't get mad about it, just advise and coax them into correct gun handling, maybe those pistols were not right for that particular student. John Shaw, stated, and it is true, firing a handgun is akin to lighting a firecracker in your hand, we know it is going to explode, and our body rejects the experience, but once understood, the mind can except it. I like to teach that way, yes it is going to recoil, but no matter what we do, it is going to happen, so, why not keep the sights on the target and get a good hit. Closing our eyes during the experience does not soften the recoil, everything will happen as normal once the trigger is pulled, so why not make a good hit???
Sir do not let this 1st experience sour you, it is noble effort, and you know what, this lady is a prime example, of why people need training. It is not rote, it is training, and training takes time, experience and effort on both sides, trainer and student.
Good luck in the future, hang in there, and remember, my best range officer students, decided, that maybe they should not do it.
To which I said to them, you were paying attention.