Series
There are 3 books in the Her Majesty's Royal Coven series.
A secret coven of witches has protected Britain for centuries, but when a young girl with unprecedented powers emerges, old friendships fracture along ideological lines. Dawson crafts a sharp, contemporary fantasy that wrestles with feminism, transphobia, and power while delivering magical intrigue.
All 3 books total 1,440 pages.
The Books Oracle — track the series you are partway through, and see what to read next.