On the order of Member of the Wedding, a heart-shaped story which questions roles and identities without mentioning either harassed word. At the beginning, Emily, married sixteen years to Porter, a professor (the scene is Virginia), mother of three boys, finds her ""priorities"" confused in a comfortably cluttered old house where every meal seems to take her unaware. Particularly now when she's asked to run for State Delegate. But just at this point a wan, inscrutable seventeen-year-old girl turns up who says her name is Alexandra (actually it's Sara), the child Emily had borne and given up for adoption before she married Porter. A few rejections and confrontations later, Emily has the courage to admit it to Porter and their children, Sara becomes a welcome part of the household and finds where she really belongs while Emily and Porter handle her not-so-nice legal parents so that Sara can feel free to make her own choices from now on. . . Simpatico without smarm for a readership--like Maxine Kumin's--which is chronologically adjustable and available.