Feminism has taken great strides in the time since we were kids. Back then, calling your teacher Mrs. when she was married was normal — and considered a sign of respect. When your teacher was unmarried, calling her Miss was normal, and also considered a sign of respect. You were seen as fresh or inconsiderate if you called your teacher by an unflattering nickname to her face — and that was about it. Nowadays, it is seen as against the tenets of feminism to call a teacher Mrs. or Miss based on her marital status. Nowadays, kids refer to all their female teachers as Ms. The same way that you address women in the workplace.