MIL doesn't seem worried about forgetting.
My mother in law is in early stages of dementia. She has Anosognosia, she doesn't realize she has an illness. I can understand that. What is surprising to me is that when a large bit of info is forgotten, like when she forgets that her grand daughter is away at college, she isn't surprised of frustrated that she didn't remember it. Is that part of it? Last Christmas she asked why they were coming to our house and we said "for Christmas Day, mom" and she didn't respond at all. Why isn't she like, "wow, I can't believe I forgot tomorrow is Christmas!"