Prelude to Destiny by Fairwren Faust

Rhea and Cynthia Evers are teenage sisters who have been shielded from the truth their entire lives. After their mother is killed in what appeared to be a robbery gone wrong , Rhea, the elder, discovers a chest full of secrets hidden away in her parents’ closet. The chest makes her think back to the night their mother died and how strange her mother had acted. Why would their mother hide mysterious leather bound spell books, odd charms, and strange pouches full of unfamiliar objects and heady aromas in her closet? And then there is the ring that Mom gave her before she died. Did she know something terrible was going to happen to her? What other secrets would be unearthed?