What is the author's style in Letters from Rifka by Karen Hesse?

Rifka's language is very advanced for a girl of her age; she writes clearly and vividly, with an advanced vocabulary, sometimes referencing Yiddish words. The Pushkin she keeps with her might be responsible for the beautiful and often poetic tone of her writing. At the same time, she does not hesitate to make jokes and write like a normal adolescent girl, using exclamation points and talking colloquially to her cousin. While Hesse keeps her writing clear and simple for elementary-aged readers, she also has Rifka use syntax that is slightly more formal than contemporary readers may be used to. This formal syntax provides a slightly foreign tone to each sentence, even though Rifka writes fluently. Rifka also seems to pick up different languages with ease. Throughout the book, she encounters Yiddish, Russian, Polish, Flemish, and English, and learns to speak at least a few words of the latter languages within a matter of days.