It got me thinking about teaching styles. B is young, and clearly feels a bit insecure, and this manifests in her trying to impose herself on the group through being unnecessarily harsh and strict. She also trots out a lot of Sensei's sayings ("In a real fight you'll be this tired after 30 seconds!" etc.) which don't have a great deal of credibility coming from her. Being a good teacher is in large part about being yourself - I think she would get a lot more enthusiasm out of us if she dropped the headmistress act.
The most useful part of the class was practicing kekomi. I seriously need to get more flexible.