I am not admitted to practice law in your state so my comments are general. also while I am an employment lawyer, I have only sued one restaurant and wage issues were not an element of that lawsuit. I did a little searching on the internet and this is what I found out: your employer can charge you for the credit cards, and she can charge you somewhat for the food, but the answer on the food is a little bit more complex.
Here is what I found http://wiserwaitress.com/the-menu/wage/
I wish you luck in your effort to be paid correctly. If you vote for Democrats rather than Republicans you increase your chances of getting better treatment at work.