Tater, my condolences. I can't imagine what I'm going to go through when I have to put mine down (or watch her die) in the near future, as she's getting old (11 this year).
I think you made the right decision. You've tried to adjust her behavior in the past, and it seems it was just senility setting in. There's no way she would have done any better in a shelter, they would have done the same within a few weeks. Nobody would have re-rescued her, not with her prognosis.
