I've seen a noticeable decline in my mother since 2016, she has also admitted "forgetting" a lot. But she refuses to get tested.
One of my siblings was nice enough to drive my mother's car with her belongings from Illinois to Indy, a week later my husband and I went to go get my mother and her other vehicle (a truck). Once my mother went through her car she said my sister had stolen her bedding and microwave from her car.
6 months ago my husband and myself helped her move into her new apt.
(55 and up community) 2 days later she told me my husband had stole $200 worth of her bedding and a microwave (yes the same things she accused my sister of stealing). I went and paid her for the missing items thinking it would make things better (of course it didn't).
Christmas Eve my sister (a different sister) and I receive separate calls from our mother telling us do not come by for Christmas, she doesn't want any gifts and she's moving back to Illinois because someone in Indy keeps stealing from her. She would not tell us who it was.
Well Christmas Day she calls me in a happy mood, I assume the "drama" had pass
This morning she tells me that my daughter has been stealing from her since this time as well and even a couple of years ago, when she was in Illinois.
So rule that out first/
Have you been in touch with her doctor?