Simple things like shutting loo door no son- in- law wants to hear or see near 90 year old on loo, even little things like knocking on our bedroom door before entering the list goes on. My partner raises these issues with her mum but nothing changes seems to get worse. Any suggestions on how to deal with this been going on for nearly 18mths. There's no signs of mental illness which would make it easier to deal with.
Get the mother to a neurologist ASAP for a cognitive evaluation. "Won't" is probably "Can't".
My mother did not start out with memory loss as the big sign of dementia. Her big problem was following instructions and doing multi-step processes. She lost her emotional control pretty early. Also her social filters that had kept her fit to be around other people for any period of time. Everybody chalked it up to being weirder with age and exceptionally difficult and trying, but it was cognitive decline.
I think it was the way mom grew up or something. They must not have ever had any privacy whatsoever which is kind of creepy once the kids are in puberty.
The worse was when she would call me to chit-chat and be pooping and farting away on her end of the phone like I wouldn't mind. Disgusting. And I told her so, like it made any difference at all.
Gosh, when I am home alone I close the door. How many of us do that?
For the bathroom door issue, you could put an automatic closer contraption on the hinges. They work just fine. Orrrrr, take the door off and put a fixed curtain up using a spring tension rod.
For the bedroom door issue, when you want privacy, simply lock the door. Put a new doorknob on with a thumb lock. Easy-Peasy.
Fix 'em all one at a time. Your MIL probably has, in some ways, the mindset of a three-year-old. Patience and ingenuity!