How do I tell my mother, who has lived with my family for 7 years and has dementia, that she is going to an assisted living facility?

You've mentioned both nursing home and asst living, which one is it? My mother-in-law is in asst living, and it's a very nice place. Nursing homes on the other hand, not so much. What about Adult Foster Care instead of a nursing home? Without knowing which one you're talking about it's hard to make a sensible comment. My m-i-l has the beginning of Alz. but she started out with dementia, and her asst living place took her anyway. She's not so bad yet.... but then again the jury's still out.