The bright unknown / Elizabeth Byler Younts.

The only kind of life Brighton Turner understands is the one she has endured within the dreary walls of a rural Pennsylvania asylum. A nurse has thoughtfully educated and raised Brighton, but she has also kept vital information from her in order to keep her close. Brighton befriends a boy whom she calls Angel (he doesn't know his name) and as the two of them learn more about what lies beyond the walls they call home, they fight for their release and eventually escape. However, the world outside the only place they've ever known is not what they expect. They have no real names, no money, and no help, and they must rely upon the kindness of strangers as they walk and hitchhike from Pennsylvania to Michigan to find their last hope of a home.