4 NUBIA EljSKOZXgAAPoND.jpg
And there's Earth One Michelle Obama and the one from President Superman's earth
Okay, I'm not sure how any of this contradicts what I said. The first two are Nubia's original appearance in the Silver Age and her return in post crisis, respectively. Not sure where the third one is from but it does look post rebirth, hence my point. The President Superman and Earth One versions aren't from main continuity.
I rest my case.
To the OP, I think the best way to describe Nubia as of now is something of a middle ground between being idealistic about man's world and being cynical about it.
Largely because writers thought the character was problematic for decades and only glanced at her for decades. They didn't want to be on the wrong end of a potential blow back.
I remember the character going viral around early 2011 and it was that combined with DC's current EIC being a fan of the character for Nubia to get a push in the current comics. Along with being a potential successor to Gal Gadot's WW after WW3 (since it looks like the film side wants WW's world to continue after the trilogy).