Pretend, then 'cave'. It's not just her life, it's yours too that'll be irreparably changed if she were to die. My short story:
At the age of 19, I experienced great blood loss in 1988 after a motorcycle accident, Oct 23. All hospital forms had been signed, then a few days later, some smartass elder said we needed a POA signed by witnesses so that NO ONE could change his or her mind when things became worse, and things were getting worse everyday, my parents and close friends were beside themselves. My H&H counts went so low, my parents were told several times over a couple of days to call family and friends in, that it might end soon. Surgery to repair damage was not possible without blood transfusions--open reduction of a femur is accompanied by lots and lots of blood loss. (After I got home, on my dad's desk calendar he had written down everyday what my hematocrit and hemoglobin counts had dropped to--I have that, I'll post that info one day.)
Panicked, my dad wanted to do a POA right then, at that moment the only 2nd witness present to sign was my un-baptized but studying, sister-in-law. Now, she's my ex-SIL and never was baptized and we're great friends. We talked about that time recently, for the first time, she said she would have never forgiven herself if I had died, and she thinks she might have given in when it came down to it.
After 11 days, my internal bleeding stopped/blood count started to rise, simply because by chance it did, NO thanks to anyone. I had surgery on Nov 9 and left the hospital on Nov 15. I was, no, I am, simply fortunate.