Where does debt go?

I am the conservator on my Mother estate. She co-signed for my daughters student loans (private), which my daughter has been paying. As my mother is 93 yo, and will not live forever, what happens to that debt if my daughter falls behind or can’t pay? Does the bank come in to collect upon the time of my mothers death? I expect my Mom to be around for quite a while more, she is a pistol! Thanks.

It will come back to the Estate to be collected.