What causes resistance to care?

There really is no way I can think of to manage this. As to eating, there is little nutrition needed to keep our elders going. I would let her pick and choose what to eat. To what end are you forcing her to eat? To prolong a very miserable existence?

You are correct that placement is the answer. Folks there are more trained and more able to simply march people through those activities of daily living, such as shower time, matter of factly. And they take guidance from caregivers much more easily than from families often enough.

Do get started on placement. This will not get better and will almost certainly get a good deal worse. I am so sorry. But you didn't cause this and likely cannot fix it. You aren't alone, little help that this knowledge may be.

It sounds like time for placement. The time for giving her choices about what to eat or wear or when to wash has long since passed.
Does she drink the Boost or Ensure shakes? Pretty much all of the clients I've ever cared for who had late-stage Alzheimer's as you put it or advanced dementia would still drink those shakes.
I am sorry to tell you but she will have to be forced into the shower or to be washed up. The time for asking her to get changed or if you can help her in the shower is long past too.
If you have to be a little mean and intimidating to get her cleaned up then that is what you have to do. Believe me, a person recovers a lot easier from a little meaness then they do from a UTI, skin breakdown, or incontinence sores which all will happen if she is not kept clean.
It's good that you have some honecare aides. She does better with the homecare aides because they aren't as familar to her as you are and she doesn't know what their reaction to her refusing and complaining will be.
When she starts up with the complaining when you're with her, tell her that's enough and no one wants to hear her complaining. Don't yell and don't get angry at her. Think of her now as an adult-sized three year-old because this is pretty much what she is now.
We do not allow children to go without eating or washing. Handle your MIL pretty much the same way.
It's going to be hard for you in the meantime before you get her placed.
When it's time for a shower or a wash-up, it's time for a shower or a wash up. This means there will be no tv, no food, no drinks, no conversation, and no attention until that gets done.
You can be more flexible on the eating as long as she's still drinking and will take a nutrition shake.

It’s time for placement. Find a MC facility you like and then you get her to go by telling her that she has a doctors appt with a new doctor that is mandatory in order to keep her insurance and you take her to MC “where the new doctor is.”Or you tell her that you all need to stay somewhere else for a few days while work is being done on the house (plumbing, electric). Take her to MC and if she asks where you are staying, say “this nice place was full so you are staying here and we are staying with friends.” I have a friend who got her mom into memory care by saying they were going to lunch at an hotel, and lunch was lunch time at the MC unit. The front desk said “your lunch reservation is ready” and they were taken to the dining area and seated. They ate lunch and then her mother was transferred to her room from there that my friend had already set up for her and that was it.

Expect a rough month with her wanting to go home but after she settles in it will get easier with time. Never perfect, but easier. Take your life back.

My LO for me:
Refuses to change clothes.
Resists showering.
No to offered drinks & food.

My LO for aides:
Will change clothes.
Will negotiate shower days.
Will try drinks & different food.

I try the same approaches.
- Offer choices where I can (red shirt or blue shirt? But it must be a CLEAN shirt).
- Respectful language
- Use logic (zero success 😩)

I don't know... Once a Mother & in charge just won't be told what to do by the youngsters??

But can still 'save face' for a 'Professional'?

If able you can employ Aides to do the showering/dressing. This may extend home care a little longer. But otherwise, time for placement.

'Late Stage Alzheimer's' seems to say it all, if we delve into the literature. Plus, we humans are still animals, part of the animal kingdom; folks who become so very disabled revert to not only 'childlike' behavior/stages but in the animal kingdom the individual who becomes less self-sufficient, more dependent, essentially is at great risk: in herds, the 'crippled' individual goes onto the 'menu', so to speak. It's no longer a personality thing but an instinctual thing: to maintain at least the illusion of coping, competency and agency as long as possible. Resistance to help may be your MIL's attempts/determination to stay relevant. And maybe even that 'childlike' rebellion, the Terrible Twos all over again. You have stepped up for her care; if she is beyond your capacity a placement may be the kindest thing for her, no judgement, just being realistic.

Your kids' needs come first. You can't focus on raising them in this environment. Placing her is not cruel; she's beyond your care, and your children should come first. If she were in her right mind, I'd bet she'd agree.

Find placement for her as soon as it can be arranged. Until then it would be worth the expense to hire outside help to save your own sanity and safety.

Sorry Cat. You can’t fix this . I vote for placement in MC. MIL is not going to start cooperating more for family members . It’s only going to get worse . Her brain is broken . She sees herself as the parent and she won’t listen to you or your husband anymore . She needs to be cared for by non family. You said she acts better for the aides. Her behavior is too disruptive to your home and family . MIL will be better off as well not seeing you all day long , because she’s on automatic to give you a hard time and be agitated when she sees family to try to boss around .
Good luck .

Our mother has this problem. When we had care for her at home, she would resist doing things, and would ask them to leave ("It's my house"). This went on for years until we only had 2 caregivers left who could sort of handle her. She has vascular dementia. Finally, we had to put her in a memory care home, where she also resists care. They are trying behavioural things and we have authorized medication if needed. I think you are going to have to put your MIL in a home at some point as there is no good solution for this problem for elderly loved ones.

Oh my goodness my heart aches for you, I understand what you're experiencing but probably not to the same degree. My mom is in mid to late stage dementia and she too was resistant to care, showering, getting dressed etc. First and foremost don't treat her like a child, though it's tempting because she's acting like one. Always use a kind and reassuring tone of voice, lay out her clothes for her, and when she gets up, walk her directly into the bathroom (don't give her a choice), turn the shower on for her, provide assistance if she needs it. Have her meal ready for her with her favorite books, magazines, puzzles, pictures, within easy reach. Turn the TV on to her favorite program if she likes that. Try not to get exasperated or impatient, though it's hard, remember she can't help it, it's the nature of this insidious disease. Also remember somedays she will be more alert and lucid than others, I've learned that with my mom, somedays she may be ready to get up at 9 a.m. somedays it might be noon or later. It's important though to maintain a schedule for her meds, bring them to her in bed if she's not ready to get up yet. If she's incontinent like my mom is, put a highly absorbent poise pad in her Depends (along with Desitin) before she goes to bed at night, this will keep her skin from breaking down. I hope I was able to give you some helpful information, believe me I've had to learn the hard way. I wish you all the best with your caregiving and always try to remember and even rejoice in the labor of love that it is. Best to you.