Laurie [narrator of Stranger with My Face] is seventeen. Oldest of three children, she lives a happy and uneventful life on an island off the New England coast, attending school on the mainland, enjoying her friends and her artistic and pleasantly off-beat parents. At first Laurie is puzzled when people say they've seen her in places she hasn't been. Then she sees her doppelgänger—and the book smoothly moves into the occult plane as Laurie learns that the "stranger with her face" is a twin sister who has learned astral projection…. One must, of course, suspend disbelief to accept the story, but Duncan makes it possible and palatable by a deft twining of fantasy and reality, by giving depth to characters and relationships, and by writing with perception and vitality about other, universal aspects of adolescent life as well as the more dramatic core of the story, a core that includes Laurie's discovery that she is adopted—a fact she stumbles on as she tries to learn about her malevolent twin.
Zena Sutherland, in her review of "Stranger with My Face," in Bulletin of the Center for Children's Books (reprinted by permission of The University of chicago Press; © 1982 by The University of Chicago), Vol. 35, No. 8, April, 1982, p. 146.