Claudia and the Great Search (The Baby-Sitters Club #33) (Baby-sitters Club (1986-1999))

It's no secret that Claudia and her sister are different. For one, they don't look alike at all. Claudia loves her wild clothes and funky jewelry, and Janine dresses. . .well, kind of nerdy. Janine is a genius, and Claudia brings home C's--when she's lucky. Claudia opens the family photo album to see what she and her sister looked like when they were little. But there are hardly any baby pictures of Claudia! And when she goes searching for her birth certificate and birth announcement in the newspaper, Claudia can't find them. Is Claudia Kishi who she thinks she is? Or is there something her parents aren't telling her? Thirteen-year-old Claudia concludes that she is adopted since she sees no resemblance between herself and her brainy older sister whom she rivals Claudia, who has always been very different from her sister, comes to the conclusion that she must be adopted.