I don't see anything wrong at all. She feels black that's fine by me. There are lots of blacks that passed for white for years.
Reminds me of Mezz Mezzrow, who insisted that he was black person in a white person's skin, much as nowadays some people of one gender will insist that they are really of another gender. And just as today the latter will act on it, Mezzrow too acted on his "unfortunate" colour.
Merrow was a reasonable clarinet player and known as some sort of jazz impresario, but was even more famous as Louis Armstrong's pot dealer and factotum and for rolling such great joints that a good one in those circles was known as "Mighty Mezz", whence the original start of the Pothead's Jazz Anthem---"
If you are a viper":
Think about a reefer, 5 feet long,
A Mighty Mezz, and not too strong
(Louis Armstrong's tune
Muggles is devoted to such exceptional "service".)
Anyways ...
The interesting part of Mezzrows's story is that all this was at a time when Jim Crow was as mighty as could be. That inevitably led to colourful situations.
If you ever want to read a genuinely joyful, positive and humorous celebration of life, his autobiography---
Really The Blues---is one that I cannot recommend highly enough. There, he also explains how he was born white but became black ("a voluntary Negro", as he put it):
Mezzrow writes that from the moment he heard jazz he "was going to be a Negro musician, hipping [teaching] the world about the blues the way only Negroes can."
As he was white, and lived when he did, it was inevitable that being a Negro and hipping the world about the blues the way only Negroes can would be quite a challenge---from both sides of the divide. He handled it admirably.
See also:
https://en.wikipedia.org/wiki/Mezz_Mezzrow