There is a very very skinny woman who attends my Pump classes. She lifts very heavy weights, sometimes heavier than me and I'm a male instructor. A while back, she used to ask the other students help her prop up the bar on her upper back before the squat and lunge tracks so obviously she can't even carry that weight. I told the class that is not allowed anymore and she stopped doing that since. She doesn't stop during the breaks. She doesn't do the stretching before the lunges or any of the other stretches. She always comes in late (in the middle of the warmup) and leaves before the cooldown so it doesn't give me any time at all to catch her and talk to her. One time she came in early and I decided to strike up a conversation. I asked her name and she was very curt. She said I won't be able to pronounce it, rolled her eyes, and turned the other way. It is very obvious that she is exercising way too much. She is really pale, very very bone thin, and lifts weights that are too heavy for someone of that body type. I'm very scared she will injure herself. I've already approached our GFM for some advice. She said we can't be sued because all the members signed a waiver releasing gym staff from any liability. But still she is a great distraction in my class and all the other students continually approach me asking me what to do about her. Our GFM believes her obvious health disorder is a matter of privacy so we don't wanna single her out during class and force her to do the stretching and the cooldown. But at the same time I also don't want all the other students in my class to see me as a pushover for letting her get away with this type of behavior. Very recently another pump instructor said she saw her one time throwing up at the back of the class into a plastic cup and one of the students said they saw blood. She attends all of the Pump classes in our gym, every single day, leaving her body no time to recover between classes. Our GFM said there is not much we can do. We can't stop anyone from attending classes they've paid for. I don't know what to do anymore. I've always thought I was a good instructor helping others reach their goal and solve their dilemmas but I think I've reached a stumbling block with this situation. Help!