Legal Disclaimer: I am a licensed Mortgage Originator in IN, FL, OH anything I say may not be applicable to other states. NMLS#1157855. You are not getting out of the mortgage and you have relinquished your rights. But you kept all your responasabilities and liabilities. The estate needs to have the heir or the owners as designated by the probate court refinance the loan which can be done and does not require a purchase money loan.
Get a Real Estate/Probate Attorney involved now. If she defaults she walks away with out injury you on the other hand suffer all injury.
Unless the property was willed to her she is a squatter and has little if any legal rights beyond normal tenant eviction rights. Get an attorney. Get the property sold off or the heir to refinance ASAP.
If you ever get divorced never agree to a quit claim deed till the other party closes a refinance removing you from the loan. This quitclaim is best done at their closing.
Demand a must refinance or sell by date as part of your divorce agreement.
With any divorce demand specific dates for everything; ambiguity allows them to cost you money.