What is the author's style in A String in the Harp by Nancy Bond?

Because this novel is written for young readers (ages 10 - 14), the language of the novel is relatively accessible, in that it is written conversationally and without large vocabulary words readers might stumble over. That said, the novel was written in the 1960's, so some of the structure of the sentences is somewhat stiff and inaccessible to present-day readers simply because the language is no longer current.