Janice Hardy 
Healing Wars: Book I: The Shifter 

Fifteen-year-old Nya is an orphan struggling for survival in a city crippled by war. She is also a Takerwith her touch, she can heal injuries, pulling pain from another person into her own body.But unlike her sister Tali and the other Takers who become Healers League apprentices, Nyas skill is flawed: she cant push that pain into pynvium, the enchanted metal used to store it. All she can do is shift it from person to person, a dangerous skill that she must keep hidden from forces occupying her city. If discovered, shed be used as a human weapon against her own people.Rumors of another war make Nyas life harder, forcing her to take desperate risks just to find work and food. She pushes her luck too far and exposes her secret to a pain merchant eager to use her shifting ability for his own sinister purpose. At first, Nya refuses, but when Tali and other League Healers mysteriously disappear, shes faced with some difficult choices.As her father used to say, principles are a bargain at any price, but how many will Nya have to sell to get Tali back alive?