If Wishes Were Earls by Elizabeth Boyle
We are huge Boyle stans so it hurts to admit this one didn't work for us quite as well as the first two books in the series. We loved Roxley's crazy aunts and the premise of a mustering, but the wider plot was hard to follow. Luckily it veered into "so weird I'm just along for the ride" so we still had fun with it.