Re: Nubia vs. Nu'Bia The major problem with Post-Crisis Nubia as presented here is that, in their attempt to defray tokenism, they made her distinctly not African.
Interesting. It would never have occurred to me to consider her a Zoroastrian character, any more than I would consider Diana a Hindu character for having dated Rama. She says it herself - Ahura is from a mythology a world away from their own, as foreign to her as the Greek gods are to the average American. Of course, she's not African either; she was born alongside Antiope and Hippolyta and made the Exile with Polly, so her cultural heritage is Greek-derived Amazon, like Diana's.
It seems to me the solution would be to explore the pre-Exile amazon culture, which is one of the major advantages to having the character around as she is here in the first place. Where did the non-Greek Themyscirans, like Phillipus and Euboea and Nubia, come from? We know there were other colonies besides the original Themysciran city-state, so perhaps they were wide-ranging around the whole of the Mediterranean. If Nubia is originally from an African amazon colony, how does that affect her take on and participation in the primarily Greek amazon society? Of course, if they're not willing to tell that story with the Bana, I doubt we'd see it with Nubia, who would lack the same comforting distance of metaphor, but it's a direction that would make perfect sense to take.
Why -can't- Wonder Woman have a black sister?
Well, because it doesn't really fit into the mythos. Diana as the only daughter of the amazons has become a fairly significant part of the story. And while that shouldn't override the concern of making an important statement, I don't think blood relation (or whatever equivalent there is for clay babies) is really necessary for that statement. Cassie is considered family, a Wonder, and Diana's heir, after all, without even having been born amazon. Or, look at the Robins. Dick and Jason were both adopted by Bruce, because there was this sense that that father-son thing had to be literal to resonate. But then along came Tim and his father was fine, for years; he had a family, he had no interest in being a Wayne, and yet all that time, he was most assuredly Very Much Robin. In fact a lot of his fans hated the adoption because it seemed to deny the legitimacy of his Robinhood until then. For Nubia to be as relevant to Diana and the wider DCU as Polly or Donna or Cassie shouldn't require her to also be Polly's kid, by the same token.
Gayatri Spivak says that brown women are tired of white women trying to save them, and that it is time for brown women to be allowed to save themselves. I'd like to see Nubia take up that mantle.
That would be pretty kickin'. Given the Wonder Woman franchise is one of the very few in comics that can get away with being somewhat socially conscious, it would be nice to see that freedom put to the cause of racial justice as prominently as gender justice. And, you know, the intersection of the two, which feminism is depressingly bad at.