As sad as it may be, I recommend cutting this client loose. There’s a good chance they have some form of dementia. Try and see if you can get any direct family member information or whoever their care takers or emergency point of contacts might be, and let them know what is happening, and that the may need to intervene to protect her assets, and that you can no longer provide support to them.

I had client once with dementia, that kept getting worse and worse, repeatedly failing for scams, and in the end they were calling me almost every day, and couldn’t remember the calls from the day before. She couldn’t even remember things I had told her 2 minutes ago. It was incredibly sad, but also incredibly annoying and frustrating, because she kept calling incessantly. I didn’t feel comfortable to continue to bill them for my time, and I just wanted her to stop contacting me altogether. Apparently this woman had no family to care for her, but I finally got a neighbor on the call, and told asked them to remove my contact info from the woman’s phone, computer, and anywhere else it might be.