I believe that speaks volumes, right there.
First, what business does a teacher have spewing her politics to minors under her authority?
Second, the fact that she would unfriend you over the question illustrates very well the difference between a liberal and a leftist. A liberal would say (among adults) I support the free exchange of ideas. The cream will rise to the top and the devil take the hindmost."
A leftist would say, "I do not have to defend my ideas. You are not allowed to challenge my assumptions. I'll just take my ball and go home."
So, my question would be, what exactly did she say to her students this morning? Think she took a moment and challenged her assumptions about her right to indoctrinate students? Or did she just plow ahead?