That all sounds pretty harsh for you, Barmaid.
I'm not sure I would try too hard to help or accommodate this lady, even if she is in her eighties...I doubt she'd acknowledge in any way that you were trying to be helpful.
In my experience, ratty old ladies of eighty-odd were ratty young ladies of 20-odd and will continue to be ratty, inconsiderate etc etc until the day they croak.
In the end you have to be yourself, though and do what you think is right. As to your neighbour, my guess is that there will be absolutely no pleasing her.
Hope the showers stop or at least slacken off.