[PSY]

I don't know if your mom could "legally"change your work schedule, as that's something the store manager ultimately creates. Your mom can write down whatever she wants, but the store manager can always disregard that and put down something else instead. I would suggest approaching the store manager and stating that anything without your signature on it should be ignored (and maybe you should consider filling out your schedule while you are at work, vs. taking the chart home with you). What she probably COULD legally do is keep you from going to work, as she is your legal guardian and has the authority to ground you if you don't meet her demands.

I second what Chris said. Validate your mom's concerns, then work out an agreement. If her concerns turn out to be reasonable (ex. your grades drop or you become extremely depressed as a result of the stress), then you will change your work schedule. If you manage to hold everything together, then you get to keep your work schedule.