Any advie on dealing with Sundowning?

Good luck Sun with the clocks going back

You can try directing the conversation to something she enjoys doing. My grandma loves clothing catalogs. So I always tell her to look at her "fashion book" as she calls it. I also leave Pringles and cookies on the table next to her recliner to direct her to have a snack.

I find maintaining a routine to help, too.

It is extremely common for elders who are in care in hospital, in changed locations such as rehabs and SNFs to become disoriented in general or at particular times, and especially at night. The internet has a wealth of information, but do know each person/client/patient is an individual with reactions as individual as their own fingerprints. Be guided by the professionals here, but if there is continued agitation and problems do make certain they check urine for infection. Often in care catheters are placed and can cause infection that later is missed along the line.