Not sure how to handle this. TW: Racism

Hey everyone. I’m not sure how to handle a situation I’m facing. I grew up in a very racist town. My ex husband and his family are racist, and do not agree with interracial coupling (🙄). We share a daughter. I have remarried, and moved to a “normal” town. My daughter is 15 years old. Recently, her dads mother asked her about the boy she is seeing, and wanted to see a picture of him. When my daughter sent her the picture (the young man is not white) her grandmother said: “I was surprised to see his picture, because he isn’t white. Im not the one you have to worry about, but you know how I feel about “that”.” 😡😡 Im guessing her “not the one you have to worry about” comment was referring to my daughters dad. Well, naturally, this really upset my daughter. My daughter is also bi…so now she is terrified to tell that side of her family anything about herself. She hasn’t answered any of her grandmothers calls since then, and I refuse to make her. That, to me, was an abusive comment. Well, now her grandma is texting me saying she needs to call me. Im sure it’s about that. I do not know how to not go off on this woman. She has done a lot for us otherwise, and I want to be HEARD when I tell her that her backwards ass fucking mindset is gross, so I want to remain respectful. Has anyone been here before? What do I do?