She toured it; still says she's not moving. Moved her thousands of miles last May (only 8 months ago), from her life-long home (Buffalo, NY) to the assisted living place in Minnesota (our home). 3 of her 6 kids here; only 1 was in Buffalo. She's declined in many ways fairly rapidly since May. Current place is not an option; they don't have enough services.
I have never seen advance warning helping the situation. And if she forgets, you'll have to keep reminding her over and over. That's too draining, so I would just tell her once and make it a positive experience. The facility knows how to handle it, so I would take their suggestions.
When I took my cousin from regular Assisted Living to Secure Memory Care, it went so smooth. I told her as we got into the car. I had her things packed in the trunk. I played her favorite music on the way and I talked about the good old days. When I pulled up to Memory Care, we were met by the Director and a staff member who got her in a wheelchair and took her straight to the dining room. They took her belongings and got her settled in. She ate while I filled out paperwork. (I would do that in advance if possible.) And when I was finished and went to say goodbye, she was sitting in her room with her roommate by her side watching tv and happy as could be. Her roommate was high functioning and told me not to worry, that she was going to look out for my cousin. She did too. They became best friends. They asked me to avoid visits for 2 weeks and I did. She did great and has been content there ever since. It's amazing how much better they fare when in place that can provide the right level of care. It will be worth it.