My sister was a teacher of 7h graders language arts. I think she delighted in giving kids the grades they "deserved". Her 2 daughters were perfect in school and both were valedictorians of their classes. They went to the school she taught at.

Over the years I met many co-workers whose child had her as a teacher. One told me my sister called her daughter stupid several times. It got to the point where I never told anyone she was my sister anymore.

And I know of at least one of her daughter's grades on a project she browbeat the teacher into changing from a B to an A. My sister can be just plain mean. She once called me a "piss poor mother" in front of my children. Broke my heart. Of course, it was over my oldest daughter's behavior that was all my fault according to my family. Especially her.