Dark Tree Shining by Paula Harrison
Laney and her friends have found the first Myrical. But there are four more hidden somewhere and if they fall into the Shadow Faerie's hands, his power will strengthen and the faerie world will fall under his dark reign.
But Laney has problems of her own. Her magic never seems to work properly and her dad doesn't want her to get involved with the tribes at all.
The second in this enchanting and mysterious faerie adventure series from Paula Harrison.
Also in the series:
Red Moon Rising
Pale Peak Burning