My father went through a round of chemo and radiation therapy that was supposed to be a success... Two weeks into remission his gait was all messed up. A trip to the doctor revealed it had metastasized into his brain, spine, and spinal chord. If he would have just left it there he would have lived longer and had a better quality of life. They offered another round of chemo and radiation but he refused. It was too late at that point. The next two months were a horrible downward spiral.
I was glad I moved across country to take care of him and keep him company in his final days. The sacrifices I made to be able to do that could never have been too great.
Be a good friend; respect and be happy for her decision. Be there for her to keep her company. Bring some weed, it really helps. Laugh with her, remember good times with her, lend a shoulder to cry on, hold her hair up when she's puking, and tell her you're glad you could be there for her. That's my best advice.
Sorry for the bad news
