This stage of life is so difficult to witness. Everybody is different but at some point she will stop eating then stop taking fluids. A person can live without food for a while but cannot survive without fluids. I saw this with my mother who passed at age 102. She had dysphagia which is difficulty swallowing and choked a lot when trying to eat. She eventually just gave up eating. Then her body started to shut down. After about a week she slipped into a coma and passed away. I am so sorry that you are going through this with your Mom. You and your Mom are in my prayers.