Checking for UTI is a good idea in my experience with my mother, who had dementia. Had your wife taken any medications?

My mother progressed in the sense that she might have a sudden burst of anxiety about a car she no longer owned being parked at some store. The rest of the time she would be seemingly okay, relatively speaking. I wonder if your wife is having some form of sundowning. The time before bed can be a vulnerable time for rationality!

Hope the doctor is helpful.