Legal Question in Credit and Debt Law in Iowa

She absolutely has the right to try to get her money back. Whether that is a good idea or not is another question. The document you signed is probably sufficient to prove that this was a loan and not a gift.

In order to garnish your wages, she will need to sue you, and win. Then she will need to serve your employer with proper documents in order to garnish. And she can forget about a Mother's Day card next year.

I would suggest talking to her about it to see if there is something you can work out without resorting to a lawsuit. Litigation takes time, money and energy, and can be difficult for both parties even when they are not family. When they are family, it is even worse. My personal policy is, if I lend money to friends or family, I consider it a gift, and then I can be pleasantly surprised if I actually get the money back.