Sooner or later, all big brothers and big sisters think it. Sometimes they may even say it: <P> If it weren't for you, I'd be the only child and I'd get all the presents. <P> But then there are other times too, times when having a younger sibling may just be a blessing in disguise. . . . <P> With simplicity and grace, the legendary Charlotte Zolotow turns her clear-eyed gaze on the conflict and bond unique to siblings. G. Brian Karas's bright, engaging illustrations bring her classic text to a new generation.