I would have them re-send any notices. Generally, if proper notices are not sent, all this does is delay the process a little bit and gives the borrower a little bit of extra time.

Either way, you need to find a way to deal pay off the debt. Without knowing all the details, some possible options are: negotiate with the servicer to create a payment schedule that is affordable for your mother, borrow money from a family member, consult a credit counseling company, or depending on the situation, declare bankruptcy.

Good luck.