Very sorry I know what you are going through. My wife has stage IV and brain tumors. She was very lethargic a week ago sleeping 20+ hours and eating the same way.... I was really scared.
The doc started her on a half of steroid pill (2mg) and she has been much better. The steroid isn’t a cure but it has improved her life. She doesn’t sleep so much and she eats much better....
Take care of yourself too.
B-in-L and Mom had/have cancer.
My heart goes out to you.
She should avoid all animal products like the plague though. Seriously. Lots of green tea. And I read that Shark Cartlidge fights cancer.
May God have mercy on your family.