That's a great point. Jo. I remember this with an aunty. The "sundowning" effect.

If she's taking a medication it might also be affecting her sleep pattern.

Some info. on Sleep Changes / Alzheimer's

http://www.alz.org/alzheimers_disease_10429.asp

Sleep Issues and Sundowning

http://www.alz.org/care/alzheimers-d...sundowning.asp