First, I'd like to explain my reaction to David's character and voice as the narrator. I think that it was a good idea to have they young twelve year old son as a narrator. He has an amazing capacity for sympathy and love, while maintaining his innocence, and giving the immediate, raw reaction a person might have to the situations. Because David is pretty young, and his life was comfortable prior to the event, he is a little short-sighted. When Uncle Frank commits suicide, he is happy, think that his death was a stroke of luck that will solve his family's problems. He says that people will grieve for a while, but things will return as they were. That was definitely not the case, because Gail, Wes, and David were ostracized from the Hayden family. That was also a sad ending to their lives in Montana.
The Jars. I could imagine Frank going crazy, smashing glass jars in the root cellar. Breaking glass makes a terrible sound. And the poor mother and father were terrified, sitting like children (according to David) on the couch. The father kept it together, and comforted the mother, who thought of how Frank was destroying their lives and efforts. Imagine waking up at 1AM in the morning, when its dark, the sound of a rapist smashing glass in the basement. I would be terrified. I came to love the character of the father, as he became the voice of morality, perseverance, and justice. He knew he had to endure the sound, and keep his family from collapsing.
I also admire the mother. She, too, tried to save her family, while doing what was right. She sent David to find his father, when the huge men of the grandfather came to forcefully break into the house and release the criminal. That was pretty impressive to me.