Unearthly by Cynthia Hand, a review

Clara has a hard time believing she’s an angel, until her mother shows Clara her mother’s wings. Clara finds she has them too. Each part-angel, says her mother, has a Purpose which is revealed when he or she is a teenager through visions. It’s very important to do what the visions are telling you to do, to fulfill your Purpose. Otherwise, apparently, you may end up as a Dark Wing, the disobedient angels with black wings who are absolutely up to no good.