Chosen Ones (The Chosen Ones, #1)

by Veronica Roth

“On your other world, you fought a battle,” Sibyl said, sinking down onto a fat tree stump. She set her water bottle down and sat slumped, her arms around her knees. She looked so small that way, the bones of her spine sticking out even through her cardigan. “It clings to you still.” Sibyl was looking down at Sloane’s scarred right hand. Sloane resisted the urge to cover it up. “That was not your battle,” Sibyl said. “Not really.” Sloane’s instinct was to argue. It had been her battle; of course it had. The Dark One had taken her brother from her. That she would fight him had been an inevitability not even worth discussing. But there was too much truth in what Sibyl had said for Sloane to deny it. It had been a battle worth fighting, but that didn’t mean it was Sloane’s. For ten years she had been jiggling her knee, waiting for something to make sense, for something new to happen. But until now, it had been too terrible to consider that there might be another fight in front of her and that it might be hers in a way the other had not.

Ok, so she is a Chosen One to Nero only?