montegomongoose
No, no, no, she meant that if white people were the small, vulnerable group, it would be racism.
Hating people for their skin is never acceptable, but power-imbalances and other factors aggravate it and make it worse. I think it's right to recognise that. It minimises discrimination to lump it all together.
My friend's little brother once called me a word more usually used for wheat-products-eaten-with-cheese. It was brattish of him, but I just hugged him, and that is the one time I have ever been called any kind of racial epithet. At the time, he was nine and he was called worse than that every single week. It would be wrong if I claimed I'd suffered racism, because it had no force behind it.
For example, in the very example you gave, that poor child you saw being insulted didn't just suffer racially-motivated mistreatment, she suffered it at school, from a teacher. That means that in any country, whatever the demographics, that incident is worse than my friend's little brother having a tantrum.