Since the bank is not party to the divorce, it does not affect your loan. Often one party agrees to assume responsibility for debts, but that does not take anyone off the hook as far as the bank is concerned. You should not have modified the note with only one of the original borrowers signing.
The cleanest way to do this is to have her apply for a new mortgage. You need to start from scratch. Once the quit claim deed is recorded, the new title commitment will show title vested in her alone.
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I thought getting old would take longer.