I agree with respecting our elders, but that does not excuse rudeness. They are NOT entitled to say whatever the heck they want just because they are old. It's called bullying in younger folks and it also applies when someone is old. Unless they have dementia or alzheimer's, then they really can't help themselves.
I can't wait to hear about your next encounter with this woman

I loved the suggestion that you burst into tears, I wonder what she'd do then