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?!)
I’m aware of two terms used in Tanach: either calling her מלכה anyway, as in אסתר המלכה (Esther 5:2-3, 7:1-3, etc.), or the more crass term שגל, “royal consort” (Tehillim 45:10 and Nechemiah 2:6, as interpreted by the conclusion of Rosh Hashanah 4a).