Legal Question in Civil Litigation in Texas

You should file a written answer to the lawsuit.

Depending on where the lawsuit originated, you might also need to file a sworn objection to jurisdiction (per Rule 120a).

And I'd ask for sanctions under Rule 13. They have no right to sue someone who doesn't owe a debt.

First question to ask is whether your mother took it upon herself to sign for you on any of her debts. Second question is for them to answer - ask them on what LEGAL basis do they claim that you are responsible for your mother's debts. (Note: they could be threatening you just to see if you are gullible enough to pay them) Once you get this information, get back to law guru, give this updated information and see what further advice you can get. You're making $900/mo. - you don't have enough money to hire an attorney and you shouldn't file a suit by yourself since you will be over your head the moment you do it.