Song of the Huntress by Lucy Holland - 7/10
Honestly, I hadn't heard anything about this book. I just saw it was an Ancient British fantasy and jumped right in.
An unexpected bonus was my uncanny ability to find sapphic books without realising 馃憖
I would definitely recommend this to anyone loosely interested in Celtic history or religion. If you're not, it's just a damn good stand alone fantasy (but you might struggle with some of the character names).