The Armor of Light: Book 2 of The Wolfchild Saga
by Karen E. Hoover
Three women. One, the first white mage in 3,000 years will begin her training at The Academy of Magi, though there is none to teach her. Another, guardian of the Saphire Flute, loses everything, yet continues her search for the Wolfchild who will save their world. The third wants the keystones for herself and will stop at nothing to get them--including destroy the girls who find them first.