IMHO, "Mistress" would have been my preference, followed by "Madame", and then the subtitles' less-accurate "Miss".
"Queen" may be accurate to the image song, but since the title is never given in the show itself, I'd prefer it not be used.
Same with "Empress" never being given in the show. While some have called Shadow Galactica an "empire", is there any official source for it being such, or did the fandom simply call it an empire?