I and Sproggy

One boy figures out how to survive New York City, his parents' divorce, and a new sister named Sproggy
Adam is a real New Yorker. He may only be a preteen, but he's Manhattan through and through, from his boys-only club to his friendship with Charlie, the building's doorman. And like all real New Yorkers, Adam takes bad news in stride. The night his parents walk into his bedroom to tell him they're getting a divorce and his father is moving to England for two years is no exception.
Adam knows he'll be OK. After all, he's got his mother, good friends, and nice teachers. But when his dad returns from Great Britain with a strange wife and a new sister for Adam, he isn't exactly tap dancing for joy. Especially since his new sister's name is Sproggy. Even worse, Dad expects Adam to show Sproggy around school. It seems like things couldn't get any worse.
But somehow they do. His friends? They actually like her! His teachers? They think she's adorable! She's taking over his comfortable Manhattan life, and everyone expects him to be happy about it. With absolutely no way out of this, it's up to Adam to make things better. After all, everyone has to grow up eventually.