My 93 year old mother is sleeping over 20 hours a day.

I'd call moms doctor tomorrow and explain what's going on. It sounds like she's at end of life now and her doctor can order a hospice evaluation for her. End of life patients are not normally hungry, but you can wake her to see if she'll eat and drink a bit for you.

This is hard, I know. I'm sorry you're dealing with such a thing and I wish you strength and Godspeed as you move forward.

It certainly may indicate this. The rule is sleeping longer, eating less. Until finally it is all sleep, bent into the fetal position, unable really to swallow food.
You might speak with doctor about Hospice care now. No one can tell how long this may go on and she has a right to comfortable care at the end, and you a right to help. I personally would never wake to feed or push fluid. This is a quality of life that really isn't good, and I wouldn't push to have its torments go on longer than they would.

I am so very sorry.

At this point what you should do is bring hospice on board. You can call them yourself or have your mothers doctor call them.
The advantage of you calling them is that you can do your research first to find the right hospice agency for your mother as they are not all created equal.
Sleeping a lot is very common at end of life, as is not eating or drinking much.
Please call hospice sooner than later. they are available to call 24/7, so you can even call them tonight so they can come out tomorrow to do an assessment on your mother.

Given your mom's age and if there is no known illness, I would suggest looking into hospice. My mom (96) gradually ate less and was sleeping more. One thing I heard was that it was probably because of her pain...but she had pain for years so why would it change her eating and sleeping now. I asked her PCP about hospice and he said we are not there yet. I tried to move her pain clinic appointment to an earlier date...no luck. Another hospitalization and visiting nurse services led to discussions about hospice. My mom started home hospice and passed 2 weeks later. By not starting earlier, I feel we missed out on help and services that could have helped us during this difficult time. Seems it's common that hospice is brought in too late.

I am sorry, but your mom is nearing the end very soon. Try to keep her comfortable. Keep pillows underneath her head. Ask her doctor about Hospice Care.

No need to wake her up or to feed her. She is winding down.

The end of life is starting from the day we are born.
Not to make light of your question or situation.
At 93, she is in the process of decline (as many of us would be).
Why wake her up to eat?
Is your intention to keep her alive as long as possible no matter what? or no matter the quality of her life?
If her body is telling her to sleep, listen. And ask yourself why you would consider waking her up to eat (I don't understand your reasoning).

Consider hiring a medical social worker to assist you - as this is a very difficult and sensitive time for you.

And, you need breaks. No one can work 24/7 without breaks. Get others in there to help you. Caregivers, volunteers, church contacts. You need more help / support.

Gena / Touch Matters

You really really really need to get hospice involved, if they are not already involved.

she's in the process of dying

Jims64: Pose your concerns to her physician.