In theory, could an attorney sue mom in the case of a foreclosure? Yes. So, perhaps you are right to a certain extent.
In practicality though, no lender/attorney is going to sue mom in the case of a foreclosure when she signed only the mortgage, not the note and received no consideration for the loan. It doesn't happen. In practicality all she loses is the home, which again, her intent is not to own it anyway.
Even a crappy attorney could defend mom if the lender were to decide to sue her in this scenario particularly since there is a quit claim deed of record signed prior to the mortgage and as aforementioned she received no consideration for the mortgage.
Do you agree with that?