Not all eleven-going-on-twelve-year-olds have their own pony, beautiful blond hair and a slim figure, a best friend like Gillian, and a new boyfriend every weekend (not to mention the devotion of Gillian's older brother Gordon). So one expects that Sarah, with all this going for her, will eventually conquer her big problem -- adjusting to the injections, diet and limited activity of a diabetic. Most of the interest lies in the day by day details of Sarah's illness -- fights with her parents over restrictions, the discovery (on the advice of a child psychologist) of hypoguards and disposable needles, and the low sugar diet that becomes somewhat more bearable when overweight sister Jane begins to count calories too. These routines are ultimately more compelling than the final test of Sarah's self-acceptance, her futile attempt to treat her own golden labrador dog Charlotte, another diabetic whose disease Sarah recognizes but fears her parents won't pay to care for. Sarah recovers easily from Charlotte's inevitable death, makes up with sister Jane who magically turns attractive and popular at fourteen, and announces her own victory over illness in a dramatic final speech to the school doctor; this resolution, like the original problem, is too clear cut to invite identification. But if Sarah is more case study than heroine, Branfield's careful, unsensationalized documentation of her medical problem will help satisfy the curiosity about illness and handicaps so prevalent at this age level.