Well, I admit to having problems with pride and anger with this woman (I have been teaching English for twenty years after all), but far more important than that was the fact that I no longer wanted to have any role in the way that child was being treated. But I did not lecture the woman, which I regret. I regret it because sometimes it is your duty to spell the faults of other people- in a cool mannered way of course. Instead, I just explained that I was not the teacher she best for her and that I was sorry but I could no longer do her lesson. The mother was angry and accused me of being irresponsible, but she never came back. But that's just the way things are sometimes.