Complete agreement on your last sentence. I meant to imply as much. Hmm. Or maybe I'd quibble and say it's nonsense both ways. Race is nonsense for a whole lot of reasons.

Does anyone bother to try to pass as white in the 21st century? The last documented case I know of is from the 1990s—Henry Louis Gates outed someone, and there are people who say the guy he outed wasn't so much passing as simply not talking about his race. In any case, today the only passing seems to be by white people who try to pass as people of color.

If you're saying Victoria might be thought "mixed", sure. But only the states that adopted the one-drop rule during Jim Crow thought "white" meant of pure European or Middle-Eastern descent. Her last name would assure anyone who wondered that she was white, assuming she had an accent that was not typical of uneducated black people.