You are not responsible for your mother’s fraud if she is the one committing it, I.e. filing taxes and fafsa forms. But if you are taking aid based on fraudulent numbers, ie taking more than is otherwise due to you, you are an accessory. I think most kids would look the other way. But if she or you are caught, it is serious matter.
We had a good friend in a similar bind, and she worked through community college and then a lore priced school she could pay out of pocket for. Her ultimate goal had strict licensing requirements and she wasn’t taking the risk. (she is in medical school now)