IF she can afford it, that's very reasonable. Like pp said, look into what happens if she declines and needs more care. Do they have assisted living, memory care, skilled nursing on-site?
Assisted living really does bridge the gap between living alone in one's home which becomes unrealistic as one gets older, and needing a nursing home, which many people don't need until the very end of life and their medical needs increase.
I always recommend reading the book "Being Mortal" by Atul Gawande on these boards. It's a really good reflection on end of life issues, our culture's view of it, medicine's view of it, and the history of assisted living as an industry. I picked it up rather randomly as an airplane read, and it's been really helpful as I'm helping with elder care issues for various family members this year.