What is the author's style in A Year Down Yonder by Richard Peck?

Characters in the rural town often speak with improper English, which lends a certain charm to the novel. For a couple examples of improper English, Grandma says, "Them's pecans," when referring to pecans in a tree, and she tells Mary Alice to "pick you out a pair," when referring to choosing new shoes from a catalog. This dialect is likely a realistic portrayal of how largely uneducated rural folks may have talked in such a town at such a time. In contrast, Mary Alice herself, as the calm and intelligent "eye" to the town's hurricane, not to mention a future journalist, speaks and writes in proper English.