blackness is her religion - and she is extremely Orthodox. Anyone living with her, in Bed-Stuy/ New York City (the mecca of American leftism) should understand it would be like living with a devout Scientologist, or orthodox Muslim, or confirmed Marxist.
You will have to get used to their views and beliefs, because it influences everything they think and do.
Not the blackness itself, which is thoroughly neutral or even advantageous in some objective contexts (athletics anyone?), but a disgusting imago built around the blackness.
It’s telling that rap is not just tolerated but venerated in that milieu (there is white rap, with due deference to Eminem, but it is much less common).
If you roll in garbage, do not expect to be told you smell like a rose by those who don’t.