Not the figurative 'average' family but the many different kinds of families -- including those where ""one person must play two parts"" -- in what amounts to an elementary sociology text. Represented (and pleasantly pictured) are the three-generation family without a male figure -- grandmother is the housekeeper, mother the breadwinner; the large family whose needs force the father to work weekends, the older children filling in in his stead; the adopted family; the small nuclear unit of father, mother, infant where ""each member is playing (only) one part."" Whatever the circumstances, ""a man's part"" and ""a woman's part"" are seen as distinct, and whoever ""acts as mother. . . cooks and sews, cleans and shops"" and comforts. Not exactly a LIBerated view; nor is the laudable stress on mutual dependence entirely convincing re expectations of good behavior (""Your family depend on you not to tell lies or cheat at school,"" etc.). Overall, broadening.but also dulling -- though an astute classroom teacher might bring to life what is otherwise better conveyed in fiction.