My mother in law hasn't changed her clothing or bathed or brushed her teeth for a week. When she stayed with us for a few days she slept in those clothes. Is it better to let it be and avoid accusations and excuses or force the issue? Btw father in law refuses to give us POA over mil while he's hospitalized. He lied and told us he already gave it to his other son- so nursing home is not going to happen anytime soon. He is being real eased on Tuesday and says he's looking forward to being back in his own home and things getting back to normal - oh geeze! Sorry for the mini rant attached to this question. We are documenting all this looks like we may have to go to court . - boo! $$$$$
It sounds like some decisions will have to be made. I can't imagine that a fall risk senior who can't remember to take his meds, would be a good candidate to care for dementia patient who needs assistance bathing and changing. What does your husband say? I'd let him take the lead since it's his parents.
Depending on MIL's level of dementia, she likely isn't able to figure out that she needs a bath and clothes. She may think she already did it and even if you remind her, she may ignore you, because for some reason dementia patients often dislike bathing. There's just something about it.
Can her husband take care of it when he gets out of the hospital? If you are up for it, then I might try to be positive and get her up and clean, but if not, wait on him to come home. I would think she would feel much better after she got a bath. I wouldn't fret about mentioning it though. She's ill. Sometimes people who are ill need our help, even if they aren't aware of it. She may not realize you are just trying to help.
As for the showering and brushing her teeth, I would ignore that for awhile... she might get back on schedule once her hubby is back home. Or buy some of those baby wipes that have a nice scent and you hand her some wipes and show her how nice they feel when you use them on your own arms and legs... nice and cool :)