Don,
I will join you in prayer for God's will and less suffering for your cousin.
God's will is sometimes beyond our understanding. I've seen devout believers suffer immeasurably with cancer and others glide peacefully to the end.
This might not be popular, but since God gives us all "free will" I sometimes believe that also extends to "will to live--or not".
I believe my own mother willed herself to die as she was so very tired of pain and suffering for acute arthritis, bone spurs and RA.
When she learned of bone cancer, undiagnosed and matastisized in her spine, she just went from a driven, perfectionistic, wild woman to a loving, gentle, at peace person because she was going home to be made perfect in the arms of Jesus!
She was given a prognosis of several months. She was gone in 15 days from diagnosis... amazingly, as one who did the budget all their married life, exactly 2 days before medicare "palative" care would have run out and gone to self pay at the nursing home!
Free will. God might let us subvert His plan for our end time if we but choose that option, but someday all mysteries will be revealed.
I will pray for your cousin.. Lord in your Mercy!