After little Abby not only cuts the hair of Kate's favorite doll but borrows Kate's toothbrush (""Maybe it fell in the toilet,"" Abby suggests when confronted), Kate has had enough. Adapting their lemonade stand, she offers Abby at a bargain price. Friend Chad points out the difficulties (""It's against the law...Your mom and dad are going to be mad. They like her""); another nice neighbor suggests that $1.99 is ""too much for such a little Homo sapiens""--he'd prefer lemonade; and Abby begins to bargain and to make friends again with her not-so-unwilling sister. But it's white-haired Nonna next door who clinches Kate's feelings by making what she describes as a final purchase: and it's not long before Kate, definitely lonely now, is knocking on Nonna's door to get Abby back. The rather long text moves quickly, enlivened by its apt, amusing dialogue. In her brisk, colorful pen-and-watercolor illustrations, Fiammenghi affectionately exaggerates the girls' expressions, setting the events in an all-white city neighborhood of row houses. A warm, satisfying story of natural rivalry resolved--for the moment.