My mom wants to sleep except to wake up and eat. Any advice?

How old is your Mom ? I can totally relate as we are in the same situation and it is frustrating, some days I wonder if she would even get up if we didn't wake her and insist on it. We have tried the same encouraging her to stay awake but nothing seems to work. We have a call in to our local area agency on aging for some assistance she we have not had any luck with her nurse or Dr. to get some assistance. DH has returned back to work FT and I will be going back with the next 2-3 weeks and she def cannot be left home alone for an hour let alone a whole day. For us COVID has just reaked total havoc although I guess we never saw the decline as much since we were not around and unfortunately for us we never got a definitive diagnosis of dementia.
Do you have any help or can she be placed in a facility ? Seems there are no easy answers. Best of luck to you.

Your mom has several physical and cognitive symptoms.
If you can embrace the fact that it’s not that she's sleeping purposefully, but because her brain and sleep systems no longer address her need for sleep in the way younger, healthier people do, you may find it a little more comfortable to relax and let yourself accept what she’s doing.

Your concern is a loving reaction to her different need for activities as they occur throughout a typical, average day, but her fatigue and desire for sleep may be a natural need for living her life at present with her many problems.

Enjoy her moments of wakefulness with her, and be as comfortable as you can with the changes her body is progressively making.

My 87 year old dad does the same. At first, when he moved in with me 2 years ago, this upset me. Now it does not bother me. He has not wanted to live since Mom passed 5 years ago. His decline was fast. I know he dreams of Mom because he talks of having conversations with her. My only concern with constantly sleeping is that his body, muscle strength, has declined so he can barely walk. He refuses to use his walker or a cane. I worry that a nursing home is in his future because I can only physically handle so much here at home. Just let her rest and pray that release comes quickly and painlessly. We cannot make them want to live.

Please just allow her to rest. I think we cannot understand how tired they get. At 78 I am starting to. Just yesterday I said to my partner "I cannot stay awake; I read a few sentences and drift off again". My Dad in his last year told me "Kid, I am so tired. I just want to sleep. I am so ready to go". My Mom didn't want him to and was at him to eat, and to get on the scale. Please allow her the dignity now just to rest until she goes to her last rest. Sleep is such a lovely thing, and often the dreams that come with it.

What’s the down side of letting her sleep?