The Tribes of Magic by Ella Summers

Conspiracies and spies are just the tip of the iceberg.

Still reeling from the calamity at the Spirit Tree, Savannah and her fellow apprentices continue their quest to discover their magic and join the Knights of Gaia, protectors of the planet and champions of humanity.
In between uncovering government conspiracies and diving deep into supernatural intrigue, Savannah discovers a threat much closer to home. There’s a secret spy at the Castle watching her every move and reporting everything she does back to the Iron Wolf, a brutal Gaian general.
If Savannah doesn’t uncover the spy before the General learns her secrets, her quest to join the Knights of Gaia will be over before it even begins.

The Tribes of Magic is the third book in the Paragons urban fantasy series, a tale of chivalrous knights, snarky heroes, supernatural drama—and one young woman’s epic journey to defy the naysayers and seize her destiny.