Spellswept

Why gender roles are reversed from our world is unclear, but maybe the mentions of Boudicca are the hints and I don't know English history well enough to get it. Regardless, women are the political leaders and heads of household in this world. Men are magic users. A woman cannot be a politician unless she is married to a magic user. Now let's subvert the gender roles.

This is a nice taste of repressed Regency romance at a fancy ball in a magic underwater ballroom. It's included with the audiobook for Snowspelled.