Can you make an employee pay out of their own pocket if their cash drawer is short for the day?

Being a GM myself I thought this was against the law to tell an employee that they have to pay what their drawer is short by them paying out of their pocket to make the drawer even for that day...? Am I wrong? Can an employer do this or can this be grounds for a law suit when an employer tells an employee that the money their drawer was short will be coming out of their pocket? This is an actual situation that is happening to my wife and my wife is actually quite the polite very honest nice quiet person who never wants to stick up for herself. The employer is making almost next to impossible for my wife to continue working there. The GM in question is showing up late with other employees that he gives rides to, gets to work undressed then dresses once he gets there, then goes out to lunch right after getting there with the friend employee that he gave a ride into work thus leaving my wife alone again after she's been alone in the store all morning already without a break because the GM and other employee decide to be late. The GM also banged on the top of my wifes car the other morning trying to scare her thinking it was funny when she was waiting in the parking lot for the doors to open to the store for a weekly meeting. This is a new GM that has come to work at her store and she never had any problems prior ever. She's never had any problems anywhere she's ever worked at all. The reason I'm not happy is she's so unhappy every day with work and it's killing her spirit and she's just not the person to stick up for herself and just overall a quiet person. I on the other hand am a GM for a very large company and give her advice on what to do, but she never does anything because she feels that it will make everything alot worse since she feels like there is not an open door policy with her bosses boss. I'm just not sure of the legality of this matter ???? If anyone could help?