A review by thebookishlibrarian
Dog's Best Friend by James Patterson

Middle schooler Rafe Khatchadorian decides to start a dog walking business when he sees his grandmother on the free-meal line at the local soup kitchen. Soon he is walking dogs for many of his neighbors and is bringing in a lot of cash for his family. Everything is going great until he realizes that he has competition: two twins start to vandalize his flyers and steal his customers. Rafe has to hatch a plan to keep his business afloat while avoiding his kid sister Georgia who he is sure is out to make his life a living nightmare.