Good stories are great to hear
I am glad that your sister was able to take Mom home with her and it is working out. I will say that what happened to you is what I fear for many. The fall necklaces are great but if Mom can't remember what it is and how to use it then it is useless. It is not the day to day that is the problem but the unexpected. It was that kind of unexpected that forced us to make alternate arrangements for Mom and Dad as well. So I do hope others take heed from this part of your story.
Your sister will get more adapt at having Mom there and what needs to be done for her. I am just glad it has worked out for all of you
Bless the BIL!!