My honest opinion is don’t put herself and you through all these treatments that may not extend life very much and will make that life difficult for her. I say this because I was in the exact situation and tried to do too much for too long instead of letting nature takes its course and letting her go with no guilt or bad memories.
You gave that sweet girl a wonderful life and she reciprocated in kind.
When I got home tonight, Dixie was bouncing off the walls and very happy to see us. Tomorrow I will spend the entire day with her and will take some time to read and reply to as many of these posts that I can.