If no payments are made the bank eventually will foreclose on the house. One question, among others, that follows is whether there are other assets in your mother's estate the bank could attempt to claim to make up any shortfall? You have options of how to handle this situation. I suggest you consult an attorney familiar with probate in your local area to discuss the situation in detail and decide on a course of action.
I am sorry for your loss. You should contact an experienced probate lawyer in the area where your mother resided. In most cases, the heirs to the estate can relinquish rights to the property - but it will be up to the creditor to decide to press for the terms of the contract through claims or to foreclose on the security interest (and that may depend on what else is in your other's estate). Again, you should contact a lawyer to review your mother's entire estate to determine the best course of action for your family. Blessings.