I believe mom to be in Stage 7 of Dementia. What is an expected time frame of her passing?

This is the link (below) is what I follow. My mom is in about 7c-d. She has not walked for over 2 years. Has not been able to verbally communicate other than yes or no to some questions and she rambles but it doesn't make sense. We have had to hand feed her for 2 years. She is totally incontinent. She cannot sit up without support. She has
a delayed swallow but does not aspirate. Mom is extremely healthy other than the Alzheimer's. It is a tough disease. We care for mom at home. She has been on Hospice for 9 months but I believe they will take her off soon. She is up for recertification in January.
When will your mom pass? Who knows? Sorry it is not easy to figure out. It is all a horrible waiting game. Bless our moms hearts for all the frustration they go through.
https://www.alzinfo.org/understand-alzheimers/clinical-stages-of-alzheimers/

Does your mom have Alzheimer's? I believe that is the only type of dementia that research has established "stages" for. Other kinds of dementia always include decline, but without distinct stages or with a progression different from those observed for ALZ. The very end stage is likely to be very similar across most kinds of dementia but the timeline may be very different.

Jjariz has provided a good source that includes "average" or "typical" duration. Notice that the stages add up to about 8.5 years. But many live with ALZ longer than that -- up to 20 years or so. Obviously these estimates of a timeline are very rough. And although that site presents the data as applying to "dementia" they really are talking about ALZ. That site is certainly worth having a look at if your mother has ALZ -- less worthwhile if she has Vascular dementia, or LBD, or Frontotemporal dementia, or something else.

Just as an example, my husband had LBD (verified by autopsy). The "average" length of that disease is about 8 years. My husband lived with it for 10. He never lost recognition of faces or names (most LBD patients retain that to the end). He had hallucinations and delusion at the very beginning (that is often the first noticeable symptom.) If you compare that to the "7 stages" you'll see that the progression is very different.

Although he exceeded the "average" expectancy for his disease, he had a very short end stage. I'd say his severe stage lasted about 3 months. The loved one of person in my LBD support group lived 12 years, but his severe stage lasted several years, and had more severe symptoms than my husband did.

I don't blame you at all for wanting some idea of how long this will last and what lies ahead as the disease progresses. We would all like that, IMhereforyoumom! There are some charts and estimates available but dementia progresses at its own pace, and it is a very individual thing. It does vary among the different types of dementia, but it varies even more among individuals, even those who have the same type.

Warm hugs to you, IMhereforyoumom. It is indeed hard to see a loved one suffering! And it is hard not to have any concept of how long this will go on. Cherish the good moments with your mom as long as you can. Come back here and discuss what is going on. We understand caregiving for people with dementia. Some of us have been through the entire journey and can be especially empathetic.

She sounds like late Stage 6. This link is the only place that I've found any info on average length of life for each stage. Stage 6 = 2.5 years; Stage 7 = 2.5 years

www.dementiacarecentral.com/aboutdementia/facts/stages/

Worst (best?) case scenario, based on your description she could have years left.

IM, I found this article here on Aging Care that hopefully can answer your question. The article deals with Alzheimer's, which is a form of Dementia. The Stages could be similar.

https://www.agingcare.com/articles/stages-of-alzheimers-disease-118964.htm