Three Dark Crowns series (Book 1 - 3) by Kendare Blake
1) Three Dark Crowns In every generation on the island of Fennbirn, a set of triplets is born: three queens, all equal heirs to the crown and each possessor of a coveted magic. Mirabella is a fierce elemental, able to spark hungry flames or vicious storms at the snap of her fingers. Katharine is a poisoner, one who can ingest the deadliest poisons without so much as a stomachache. Arsinoe, a naturalist, is said to have the ability to bloom the reddest rose and control the fiercest of lions. But becoming the Queen Crowned isn't solely a matter of royal birth. Each sister has to fight for it. And it's not just a game of win or lose...it's life or death. The night the sisters turn sixteen, the battle begins. The last queen standing gets the crown. 2) One Dark Throne The battle for the Crown has begun, but which of the three sisters will prevail? With the unforgettable events of the Quickening behind them and the Ascension Year underway, all bets are off. Katharine, once the weak and feeble sister, is stronger than ever before. Arsinoe, after discovering the truth about her powers, must figure out how to make her secret talent work in her favor without anyone finding out. And Mirabella, once thought to be the strongest sister of all and the certain Queen Crowned, faces attacks like never before—ones that put those around her in danger she can’t seem to prevent. 3) Two Dark Reigns Queen Katharine has waited her entire life to wear the crown. But now that she finally has it, the murmurs of dissent grow louder by the day. There's also the alarming issue of whether or not her sisters are actually dead—or if they're waiting in the wings to usurp the throne. Mirabella and Arsinoe are alive, but in hiding on the minland and dealing with a nightmare of their own: being visited repeatedly by a specter they think might be the fabled Blue Queen. Though she says nothing, her rotting, bony finger pointing out to sea is clear enough: return to Fennbirn. Jules, too, is in a strange place—in disguise. And her only confidants, a war-gifted girl...