Could someone have, or build, a Mother-in-law apartment on their home with the proceeds of the sale of the older members' house? That is, if they own it.
Or rent a small apartment near one of the children?
I'd get in touch with THEIR local senior citizens' group and ask them for suggestions. Our local one has some new apartments right across the street from our local Senior Citizens building. Or get in touch with the same groups in each of the children's towns. They might have some good leads.