Services are available throughout Free Clinics and AARP, also Sosial Security possibly if she ever worked and no longer is able to. I cared for my dad for the last several years of his Alzheimer's and volunteer as relief for caregivers of others with the condition, as well as a friend with Parkinson's.
I would strongly encourage you to somehow get a basic physical exam for her, a thorough one that will cover all blood work, checks hormones and glands, and do some basic brain scans to eliminate any chance of slow-growing rumors. Eliminate all the myriad other things that could be responsible for her behavior.
I'm glad you founded this site.
Roadie