Oh man, I'm sorry she's going through that. When my mom broke her hip, she didn't have surgery for a few days due to lack of availability. She was a little stubborn with her rehabbing, but she now gets around relatively fine on her own. She'll never be able to live alone though.
Had to do the medical POA for my parents (sister and brother are exec of the will and something else). When my dad was at the tail end of his life, they gave him the option of having a stomach tube put in (he was having chemo AND radiation), but he waited too long to make the decision for himself (and it was too late for him to make it and realistically survive).
So it was up to me (I asked my siblings and mom for a consensus), and we decided to not have the surgery, and put my dad in hospice. I know that palliative care is there to help, but imho, it didn't make things easier.
Having to decide your parents fate is a horrible thing to do. But I knew my dad wanted to pass at home, and not alone in a hospital. I'm sorry you're going through this, but I imagine your mom is probably like my dad, in that he was scared and lonely. He was also still a stubborn old fart, up until the end.
End of life care is about making them comfortable with what is happening. I can't imagine getting the double whammy like what you guys are getting. At least we *knew* about my dads cancer before he went in to hospice.
Now if you don't mind me, Im going to quietly weep as I remember my dad.