G'day sophiesmommy, and
. God bless your Mum! Aged 83, in a nursing home, slight dementia and does not understand all that is going on, heart problems, aneurysm and now on dialysis. Oh dear!
I understand your confusion and worry. In her more lucid moments, can you have an honest discussin with her about her conditions and her future. A very personal problem, and one on which I cannot and will not give advice. Other people on site have experienced similar circumstances, and I hope they respond to you.
As I said, God bless your Mum, and you also.