When my dad became terminal, and also had dementia, we put him into hospice so that he could get the most supportive end of life care. Has hospice been suggested for your mom, or is the suggestion for palliative care, which can also be good? Your questions are important, but may be difficult to answer, as these things are often variable. You might ask her doctor (s) directly or discuss with a hospice or palliative care doctor. Do you have any support yourself or are you the only caregiver? Medical social worker might be able to tell you the best way to get some additional care. Personally, I've found hospice very helpful in several situations--have used their social worker, chaplain, nursing, and more. I'm sure you'll get some good feedback here--and wishing you all the best with this difficult time.