Lower economic social crowd?

This woman that I know tells me that a school that is 80/20 white you are not going to have the same problems as a school with 40/30,she also says the more diverse a school is the more problems it will have! I was really upset at this and let her know , she is a member of the local pta, so Iam questioning her racist thinking, do you think Iam making a big deal over this kind of talk-thinking ?