Thanx for posting this - as painful as things are for you at the moment.
An elder, who was like a dear Uncle to me for over 35 years, died of a similar illness a couple years back here. I think it was AML. He of course refused the treatments. I was already a 'shunned' one, and he refused to see me or acknowledge my loving support for him. He likely would have succumb in time, but he was more intent on keeping the legalistic religion fore in his mind than anything else. I watched him die at a distance. It still hurts me to think that I could not be there to support him. So do all you can to be there. Her decisions are her's to make, though we wish they would be otherwise at times.
Hugs and peace to you.
Jeff