Oppression (Children of the Gods #1)
by Jessica Therrien
Elyse knows what it means to keep a secret. She's been keeping secrets her whole life. Two, actually. First, that she ages five times slower than average people, so that while she looks eighteen years old, she's closer to eighty. Second, that her blood has a mysterious power to heal. Now, only one other person in the world knows about her age and ability. Or so she thinks.