Don't know where else to post this

Recently learned that some of the family members on the side I married into make comments about me behind my back. Turns out they're more racist than I thought. My looks weren't a huge issue for me until I moved to the south. The comments and stuff don't bother me because my MIL and FIL are amazing and that's what's important to me. I am, however, worried about comments that might get back to any children I might have. My potential future children could look all kinds of ways. My siblings and I are a diverse range of height, hair types and skin color. All from the same parents. Genetics are amazing that way. How do you teach a child to ignore racist remarks?