Mom has mid-stage Dementia, obviously advance. I say mid stage in that she can still get dress, eat, and laugh at stories we tell and recognizes her children. Her only other ailment is Hypertension and early kidney disease. Her hypertension has been regulated for years by her medication and the kidney disease was just recently revealed. (one kidney if perfectly fine and functional, one had three spots on it). No diabetes, no recent stroke (small undetected one las year showed on CT). All of her tests were negative and chest x-ray clear. What could be causing her to sleep mid-day so much?
Your Mom may sleep so much because when They are asleep they are not in a restful sleep. If she do not reach a state of REM sleep it is likely that when she wake up she will not feel well rested.
My MIL had vascular dementia and when she was mid-stage the nursing staff worked to get her into the habit of taking an afternoon nap from 1-2:30 - she was sundowning and that nap really helped. She would go through periods of sleeping a great deal, morning and afternoon naps, and she would go through napless periods.
How old is she?
I am new at all of this stuff, my mom had a stroke within the last 6 months, she doesnt sleep well at night, but boy can she sleep during the day!