Oh, God. I'm sorry you're in this position. Does Miss B have any relatives that you know of? Failing that, is there some kind of senior services agency in your area that you could call for advice? That's all I can think of. You're right that it doesn't sound like she should be living alone. And I can't even imagine what her landlord will do when s/he sees the house. But I suspect that if you really took responsibility for her it would consume your life, and as much as you want to fix things, you can't let that happen.

{{hugs}} I hope someone's able to help her. How awful.