"Mandy" by Julie Andrews Edwards. Read by the author. Newman/Dove (two cassettes, unabridged). In a warm, quiet, Poppins-worthy bedtime-story voice, Julie Andrews tells her charming tale of a 10-year-old orphanage girl who discovers a real-enough deserted cottage just over the garden wall. She makes it a home of her own, at the cost of deceptions and prevarications that have dire--although temporary--consequences, thus creating a story that is not only full of event and suspense but becomes quite unobtrusively instructive about the wise way to conduct one's life. A small perfection, heaven-sent for sleepless or ailing youngsters. Information: (213) 550-1806.