My mom is 92 with advanced dementia. She is now on hospice but they can't really say how much time she has left. Any thoughts?

It sounds like being under Hospice care is exactly where your mom needs to be at this time in her life. And just because she's under their care, doesn't mean that she will be dead in 6 months. My husband has been under their care now for 22 months. It should bring you some comfort having extra sets of eyes on her with the nurse coming weekly. Hospice should also be providing aides to come out twice a week to bathe your mom as well, so you/she doesn't have to be paying for an aide out of pocket, as that is all covered by Hospice. Take advantage of all that Hospice has to offer, as it can only help you and your brother have more peace of mind in your mom's care. Now I am more than aware that a lot of the programs Hospice normally offers has been put on hold due to Covid, but that too will change in the future. And the nice thing with being under Hospices care, is that when your mom requires more care (and she will), they will increase their visits as well, and supply you with any needed medications, medical supplies, like hospital bed, diapers, pads, creams etc. So please don't second guess yourself. You're doing what is best for your mom at this time in her life. Wishing you God's peace.

There were three main things we were told to look for that indicate end of life would be soon, and for our parent they proved true.
1. No longer eating or drinking
2. No longer communicating
3. Sleeping a deeper, more persistent sleep than normal

Yes, if she qualified for hospice, it's absolutely the right thing to do. Why do you have reservations about doing that? It's never too early to be evaluated for hospice. The sooner, the better. Being on hospice doesn't necessarily mean she has only 6 months to live. My wife was on hospice care for 15 months. Some people are in their care for years. There are signs of active dying where the time left can be estimated, but apparently your mom isn't there yet. Hospice will provide her with painless, comfortable end of life care. Hospice offers some special benefits also such as music therapy. Ask to have one of their music therapists visit mom and play some of the old songs she might remember from her early days. Even though her memory has been affected, she will recall songs of yesteryear.