Is constant sundowning indicative to a particular stage in the dementia process?

Sundowning is characteristic of moderate dementia, and especially of the Alzheimer's form of the disease. It happens to most people with dementia at some point - with or without medications.

In fact, many people attribute early dementia to normal aging - but when the person begins to sundown, it becomes very clear to family members that something is very wrong. For example, the family goes out to a restaurant for a social event and their loved one starts acting very "odd" as evening approaches.

It's indicative of a need to adjust medications. Get a new MRI or CT of her brain and see the Neurologist or Gerontologist.