Unfair and unfortunate as it may seem, your mother may remain responsible for the mortgage on the property, even though she understood that she was free and clear of any
obligations on it after signing a quitclaim deed.
In legal reality, a quitclaim deed only applies to the title of the property and not the loan obligation. As the next quick steps, your mother should consult with the attorney who handled their divorce case to see whether the mortgage remained in both parties’ names when the deed was executed—or hire another legal expert to interpret that document if it doesn’t seem clear on its face.
In the most dire of scenarios, the original loan documents may still be held by your mother and father jointly.
Before she pays a cent, however, you should encourage her to review the settlement agreement to see if the attorney added a clause to protect her from having to pay this obligation.