A DIFFERENT KIND OF SISTER

Sally has a natural aptitude for riding; if she had more horse sense she'd realize that much-admired Amy is using sweetness as a cover because she is afraid her horsemanship will be challenged. Older sister Debby, just deinstitutionalized, is retarded and Sally thinks that's what makes Amy turn unamiable. Actually, Sally is more discomfited about her sister than anyone, a point she eventually acknowledges. Uneven handling of the situations-especially several tonguelash-guilt-apology sequences--often makes this story unappetizing, and thirteen-year-old Sally's social obtuseness is too prolonged to be convincing.