Racism 😞

I have 2 nieces 1 nephew all part Hispanic very beautiful kids. I am about to give birth to a daughter that will be half white half Hispanic. My oldest sister the mother of the mixed nieces and nephew likes to post stupid Featherwood stuff on Facebook. I can't understand this and I try to explain to her how hurtful and disrespectful it is. She didn't raise her kids so I guess she feels no loyalty to them. I have told her many times if she keeps doing this kinda childish stuff I will not allow her around my daughter. Am I being to harsh about her childish behavior.