After 8 years, it is just possible her boudaries are shifting for some reason. Could be personal, could be professional. Where in the past she might have been willing and able to accept texts at any quantity at any time of the day or night, perhaps she feels differently now. Boundaries do change for people, particularly over such a long period of time. Part of what we have to learn as adults it to understand how other people's boundaries do shift at times and we can still respect those boundaries.

A change in boundaries is not saying you did anything wrong at all. Boundaries aren't about punishment.