"Dear Sister,/ They told me to draw a picture of you for your baby book./ Here you go." So begins a series of illustrated letters from a brother to his younger sister, a less than welcome addition to his life--at least at first. The letters are accompanied by Joe Bluhm's gag-filled illustrations, some in what suggests a child's hand. The letters highlight the brother's frustrations: "Congratulations! According to the judges' calculations, your Cry Olympics scores place you in the top 3% of three-year-olds nationwide." But he has to admit that, by his sister's 10th birthday, she's no longer his nemesis: "Whininess: Could be worse./ Annoyingness: Could be worse." Alison McGhee (Pablo and Birdy) is so unremittingly funny that readers may be caught off guard toward Dear Sister's end, when it's time for the brother to go to college and--who would've thought?--both sibs are heartbroken. --Nell Beram, freelance writer and YA author