Sorry to hear you are going through so much stress Kathryn. Its bad enough having to watch your mother “slipping away” without having the added strain of isolation caused by your sister’s detachment. As Velvet says, siblings cope differently with family problems. I remember when my own mother (rip) had to move to a nursing home there was terrible dissension in the immediate family. At the time there were three sisters and one brother and because I was the youngest, I was always looked on as my mothers pet and now her little pet was turning into a big bad wolf and “putting her mother away”. It was a most awful time. All the rivalry and dynamics from early childhood reared their ugly heads and even now when I recall some of the scenes, I feel like putting my hands over my ears and letting out a loud scream.
Just hold on to two things Kathryn.
You are doing what is best for your mam.
Things will calm down as time moves on.
Just use the “one day at a time” motto.
Everything will work out in the end.
You are in my thoughts and prayers at this difficult time.