Katherine Paterson has a knack for using really simple language to convey feelings and themes that are anything but simple. She does this in part by writing in a way that's plainspoken and honest. Take a look at this scene when Louise has just found out that the Captain is sending Caroline to a fancy boarding school:
I jumped toward the kitchen with the excuse of making tea. I could hear the Captain talking on to Mother and Caroline about the academy he knew in Baltimore with the wonderful music program. The words roared in my ears like a storm wind. I put the kettle on and laid out cups and spoons. Everything seemed so heavy I could hardly pick them up. I struggled to pry the lid from the can of tea leaves, aware that my grandmother had come in and was standing close behind me. I stiffened at the sound of her hoarse whisper. (14.85)
Our author shows us a character who's falling apart on the inside yet is desperately trying to keep it together in front of her family. The words don't get melodramatic, though—they're very understated. Sometimes, the most effective way to say something is just to say it plain and simple. We like that.