New kid in Fei's class

There is a new girl in Fei's class.  It's her first week and she is creating chaos already.  I've been telling the girls for two days to just stay away from her.  Today I came home and they ran to me to tell me that the new girl told N, who told L, who told S, who told Fei that she thinks Fei is stupid because she is Chinese.  I'm spitting mad about the incident.  I get that she's had problems at her other school, that she's new and likely scared etc. but racial hatred from such a young child is simply intolerable.  She didn't come up with that on her own.  I don't relish meeting her family!  Apparently she has already been sent to the office but the girls don't know for sure what for.  Nice way to end the school year.  Sadly Fei wasn't the only target, the kid has issues with skin color and was just as awful to other minority children.  So...how do I proceed people?  What would you do if it was your child?