Mother is going downhill and for the past two weeks she keeps saying she is dead. Should I call her doctor and see if a home health aide can come check her out?

I would listen to your mom. Sometimes people that age say really dramatic things, especially when they are in pain, but sometimes they are telling you exactly what is going on. I would get her to the doctor, have them check for signs of infection or another acute/urgent problem. If their office will send someone to the house, that is great. If you think it's a sudden decline, it might be good to talk with her doctor about a hospice evaluation. The people will come out to your home a couple times a week to check on her -- if you are on your own with your mom, it's nice to have people who've been through it before keeping watch for signs that she's going through a change. They can increase comfort measures for her, and there's someone for you to talk to if you have concerns. I'm sorry your mom is having trouble. I wish the best for you and for her.

If possible take your Mom to her primary doctor to see what he/she has to say about your Mom's current condition. The doctor may recommend skilled nursing care at home, or at a nursing home, or depending on what the doctor finds, maybe will say it is time for Hospice, which can be accomplished at home.

If you are finding that it has become much more difficult to help Mom at home, it is time to bring in some outside help if Mom can budget that cost and the biggee, if Mom will accept outside help.

Yes, 90+ year olds will sleep a lot. They have lived a long long life and are tired. My parents [also were in their 90's] would do a lot of cat napping during the day. Dad was on a walker, Mom on a cane as she refused to use a walker as she felt it made her look old.... seriously?

Or we just need to let nature take its course. There could be a time when 911 is needed, hospitalization, maybe rehab [yes, even at 90], then evaluation to see if she could go home or stay in long-term-care. I had to do that with my own Mom.