Does anyone split living with sibling of a parent? Currently lives with me in a MIL suite but we need a break.

Your first step is to call your siblings and ask them what they think about assisted living. That your mother "doesn’t want to go to an assisted living" is not a valid reason to continue your current living situation. After 8 years, you have been more than generous with your home, your time and your money. I'm sure it's cost you financially to have her living with you and your husband.

I can barely get any of my BILs to visit FIL let alone take him into their homes for weeks at a time. The last time FIL stayed with any of his other sons was 2 years ago, and that ended badly because BIL works long hours and his wife has her hands full with her mother who lives nearby. My other BILs have problems of their own including a marriage that's ending.

When children are involved, they will be affected by their grandmother's needs and their schedules/routines will be disrupted, which their parents may be reluctant to do especially when your mother is "Fall hazard, mostly sedentary and overweight".

That said, you and your husband most definitely need a break, and perhaps a permanent one. Start touring assisted livings and get your siblings on board.

My daughters godmother did this when her husband passed, and I know she often said she felt like "she had no home".. She moved every 3 months.. it was good for the kids but maybe not so much for her. My own mother lives with us for over 5 years now, and still feels like it's "not her home",, But no place will, her home is where she lived with Dad. Your mom may be easier about this. But I am lucky in that my Aunt takes my mom for a week or two every few months, and mom LOVES that,, she is with her sister! And we take my Aunt for a week for so every few months, and on all family vacations.., so both sides get a break. And once a few years ago my cousin in Tx took both mom and Aunt for 6 weeks,, all of us kids were in heaven, and much refreshed when they came home!

Are your siblings on board with this plan?  That is your biggest hurdle.  I hope they are, that would be amazing.  It is in your mother's best interest.  Once burn out and resentment set in they are hard to recover from. 
There really isn't any instruction platform for it.  Just have a talk with the siblings, let them know this is how you are feeling, that you have had mom for eight years and it at this point is causing issues in your home and you need a break.  Let them know your ideas for the rotation.  This is only fair if they are financially capable and they have space.  If they are not on board, possibly check into in home assisted caregivers that can come out to the house and assist with your mother.  I wish you luck with the siblings and know that for eight years being the one to do it all is something to be proud of.

A friend of mine was part of The. Ideal. Solution.

When her dad started failing, she and her 2 sisters - all either retired or local, no kids at home - took turns moving into his home for 4 months at a time. Gentle for him, and the sisters were lucky to be able to work it out.

You don't indicate that dementia is an issue at this point in time. But if it becomes so, as a general rule, moving her around will only be very disorienting.

You and she might be better off setting her up in an Assisted Living place that has tiered transitions into more levels of care. That way, if/when moving is necessary, it's in the same facility where she can still possibly continue to visit and/or dine with some of the same people with whom she has become acquainted.

You have previously posted: "Mom lives in an apt on my property at 83. Not willing to drive but still fairly mobile except for going out in heat, heart and blood pressure problems, fairly home bound. I have a full time job, some business travel and hubby travels rarely. No outside help from siblings."

How was is that Mom ended up living on your property? How many siblings do you have? If there is "no outside help" from them, how likely is it that you think they will agree to take turns housing your mother?

What are your mother's finances? Does she pay you rent? Or anything at all? If not, then why not? Would she be able to afford Assisted Living?

What are the plans for when her needs increase? You state that you work a fulltime job, so what will happen during the day when you aren't there?

Your mother may not want to go to Assisted Living, but she is being selfish if she expects you and you alone to give up your privacy to take care of her.

My Father has 5 sisters. He and oldest sister "A" are both disabled and cannot take care of their Mother. The four able sisters rotate taking care of their Mother this way: Mom lives with "K" during the school year so Mom can be there when kids come home from school. "M" takes Mom during the summer. "H" takes Mom during holidays from Thanksgiving through New Year. "N" takes mom on family vacations. No one gets "stuck" with Mom and mom does not get bored living in one place.

It will depend on her mental health in relationship to dementia - it is extremely hard on those with dementia to repeatedly move so you may need to think about care for her

FYI .... nobody puts on their bucket list that they want to go to AL or NH so her saying she doesn't want to go isn't unusual but also has she seen one recently? - she is probably remembering the old style ones not the more inter-active ones of today -

My mom didn't want to go either but within days she was blooming with so many to talk with, the activities [10 X a week + religious ones] that she convinced herself that she was part of the recreation staff - prior she was with my dad who played on his computer all day & she just watched TV except for meal times - she would be so trilled when she won a mini chocolate bar at bingo - she would often tell me that you could eat off the floor because they were always cleaning [she loved seeing the floor cleaning machine going down the hall]

It can work though I'm sure it would not be without its challenges.

My mom lives with hubby and I (4 years now) and she goes to my sister's for 3 - 5 nights every month. It reallly helps give me a break to be in my own house all by my lonesome.

Your mom may not agree, but that's OK with me, as long as your siblings are on board. A few months at a time may be a little too much for them, depending on their setup. Maybe 2 weeks to start with? That would be a nice break especially if it can happen on a regular basis.

Splitting "Grandma" up among the siblings worked great when my grandmother had a 2nd heart attack and my parents didn't want her living by herself. There were 3 siblings. She would stay with us for 2 weeks, then go to her daughter's house for a week or so and then to the other son's house. She loved getting to visit with the grands and all but she would always be glad to get back to our house. It does work better than people realize under the right circumstances. She would "piddle" around the kitchen & wipe down countertops or little things she liked to do. Here's the sticky part for others though. All three siblings lived within 15 miles of each other so it was easy to move her around. Nowadays, some live 100 miles away or even in another state so "grandmother" may need to stay longer stretches like a month each. But that would be great too. Something to think about. It worked for my family.