Repetitive, Playful, Vague
The author of The Boxcar Children was a first-grade teacher, and one of her goals in writing the book was to make it both entertaining and easy to read. Her writing style has a lot in common with books for very small children—short words and a lot of repetition.
An example in the book itself illustrates this technique. In the book, Jessie teaches her 5-year-old brother Benny how to read. The first sentences he learns are: "See me. See me run. I can run. Can you run?" (10.83). Benny's reading lesson sounds a lot like this bit of dialogue from Dr. Moore:
"Look, Mother!" he said. "Look at those tools. Look at the shelf. Look at my hammers. One, two, three, four hammers. Your hammer, my hammer, and two other hammers." (7.55)
See the similarities? Yeah, we thought so. Sometimes, all of this repetition feels like the author is really belaboring a point, but sometimes, she uses word play to make the repetition more fun. Consider this paragraph, which uses the word "watch" in two ways:
Benny climbed into the man's lap. "Have you got a dog?" he asked.
"No," said the man. "He is dead now. But you can see him in my watch. Here it is."
Benny looked at the dog. "He looks like a very good dog," he said. "I have a dog, too. His name is Watch." (11.56-11.58)
One thing that's interesting about the story is that it spends a lot of time on details—we know exactly what the Alden children are having for dinner at any given time—but quickly brushes over huge plot points with no explanation. How did the Boxcar Children's parents die? Unclear. Why have they never met their grandfather until now? No one knows. Why does Dr. Moore decide to keep the children's existence a secret from Mr. Alden? No idea. The author leaves these mysteries to our imaginations.