Well, about the famous American Nubian Princess ???
I'm not sure because I haven't meet anyone knowing about this expression. But this is my idea according to the facts that she must wear a crown as any princess, she could be seen in many places in Paris, specially along the Seine, she has several names and identities and could also be African. For me, it's THE STATUE OF LIBERTY, of course !
Why ?
Because, she wears a crown with seven branches, she can be seen near PNY in front Arts et Métiers museum, at Alma bridge, and near Bir Hakeim bridge, she's also known as "Liberty enlightening the world" and Bartholdi was inspired by maybe his mother, maybe Sarah Coblenzer, Isabella Eugénie Boyer ??? and finally before Bartholdi had another project inspired by the colossus of Rhodes or the lighthouse at the entrance of the port of Alexandria.
What do you think about that ?