I agree--the teacher was out of line and should be spoken to--this does remind me of a joke: 1st day in kindergarten and the students are discussing their summer vacations in front of the class. One child said "I rode a choo-choo". Teacher corrects the student- "you mean you rode a train". 2nd student said went to a camp where she rode "horsies". Again the teacher corrects her and tells the kids since they are in school, they must use the correct, grown-up terms for things. She asks Johnny to speak about his vacation. Thinking about what teacher had said, he stated "We went to Disney World where I met Winnie the Sh*t".
Teacher really need to be careful about their instructions.
Teacher really need to be careful about their instructions.

Second of all, what difference does it make to be called mommy, mom, mother? Atleast the child isn't showing disrespect by calling you obscene names or something.