What is the typical dementia progression rate?

There is no time table. You will have to keep an eye on her symptoms.

You asked this exact question on Feb 9 and received responses:

https://www.agingcare.com/questions/my-wife-has-mild-dementia-now-what-can-i-expect-as-to-progression-year-when-i-will-need-some-home-ca-456219.htm

There really isn't a typical case. It is as varied as it can be and not predictable. Your doc may give you a good idea based on what he has seen with the patient over time.