Wow. I actually have zero answers for this one. I have no idea why a racist would marry an Indian man. The closest I can come to that is my ex, with whom I had 3 children is racist as hell (but he became progressively racist over time). he bitches about Black people (and anyone else of colour) all the time, uses derogatory slurs, and he knows full well his kids are part Black. I've called him on it, I;ve asked him about it and all I've ever gotten is, "yeah, but they don't look it." Okay, that's about the dumbest response ever, but that's a whole other kettle of fish.

Maybe your mother really has issues with her own self-worth and this is her way of trying to elevate herself over others? I don't know, like I said, I literally have no answers for this one.