This is book number 6 in the Dragon Girls series.
The Treasure Dragon Girls — Quinn, Aisha, and Mei — all have incredible magic inside of them. They can transform into powerful dragons when they visit the Magic Forest. There, they help the forest’s Tree Queen protect this special place against the troublesome Shadow Sprites.
Quinn's jade dragon powers are uniquely suited to help her find the last remaining item that the Shadow Sprites have stolen from the Tree Queen: the Heartstring Violin. The sprites are growing stronger by the hour, but Quinn isn't worried. She is ready to fight back — with the other Treasure Dragons at her side.