The Lunar Chronicles Book Series

Cinder, a skilled mechanic, is a cyborg. She's a second class citizen with a mysterious past who is reviled by her stepmom and blamed for her stepsister's illness. But when her life became entangled with the handsome prince Kai's, she suddenly found herself at the center of a galactic struggle, and a forbidden romance. Between duty and freedom, loyalty, and betrayal, she must discover secrets about her past in an attempt to protect her world's present and future.