The Rambam in Hilchos Melachim U'Milchamot 1:5 writes:
אֵין מַעֲמִידִין אִשָּׁה בְּמַלְכוּת שֶׁנֶּאֱמַר (דברים יז טו) "עָלֶיךָ מֶלֶךְ" וְלֹא מַלְכָּה.
We may not appoint a woman to the kingship. As it says, “upon yourselves a king” (Deut. 17:15) - ie a “king” and not a “queen”
While this explicitly teaches that we can't appoint a woman to royalty, what if her husband is king? By extension, would this mean that her title is now "queen?"
(feels like it could be tricky to call her that- there could hypothetically be 18 queens concurrently?!)