Say What??!! I've never hear of anything as crazy as this before. How old is your sister-in-law, and what kind of care does she need? Is she able to remain in her home or will she have to find other accommodations for the week?
When she leaves the facility for the holidays, is she going to the home of a LO? If so, you can hire a reputable in-home service to stay will her (we use Visiting Angels). If she has no place to go...not sure about that. Maybe someplace like a Resident's Inn with the help of an in-home service? Is cost an issue? Maybe it's just me but seems odd that they shut down completely...is it a group home? Maybe time to find a different facility? I agree with GardenArtist to ask others there what they do.
I have never heard of a facility closing down for Christmas. I would wonder if this is even legal. What are people suppose to do who don't have families.
What do other residents do? The staff should be able to offer some suggestions.
How old is your sister-in-law, and what kind of care does she need? Is she able to remain in her home or will she have to find other accommodations for the week?