A vignette, merely, and quite obviously designed to accomplish certain purposes. But the narrative--put as the words of a black girl of nine or ten--is just sufficiently casual, and the pictures are more than sufficiently compelling, to engage a youngster's interest in the non-events. The narrator and brother Bootsie are spending their vacation with Grandma Mag, a thoroughly modem, young-middle-aged grandmother with pep, imagination, and only a modicum of quirks. ""She wears sneakers all the time""; she ""doesn't like to cook"" (""But we always have gingersnaps and cheese with sassafras tea for dessert""); and when she takes the kids downtown, the three ""window wish."" (""Grandma says when she was little she would catalog wish."") On certain days of the week, each of them does the wishing; on Sundays, ""she doesn't let us wish""; and ""next week. . . Bootsie gets to wish every day--it's his birthday."" That's it--but frame by frame, each of the situations reflects child likings and feelings. And the small city setting is a welcome change from the common inner-city or rural-fastness extremes.