Jeanette’s family has to take desperate measures to make money as their father squanders most of it through his drinking habit. Several times throughout the story, Jeanette and her siblings encourage their mother to leave her husband so they can live on welfare—and several times, her mother takes up teaching positions, but they still end up drained of their resources every time.

At one point, when the children take to dumpster diving for food and resources, the attempts to earn money get more delusional and dangerous. Jeanette and her father go to a pool hall and try to hustle some pool players to earn extra money, but this results in Jeanette’s near-rape and refusal to work with her father’s schemes any further. Additionally, her father builds a device he calls “The Prospector,” which is intended to dig for and sort out gold nuggets in the yard but is unsuccessful.

The Walls family is perennially short of cash. Primarily, this is because the head of the family, Jeannette's father Rex, is too proud, too independent, too stubborn, to work for anyone else. He wants to be rich, but isn't willing to put in the necessary hard graft to make it happen. More than anything else, he feels that working for the "boss man" would somehow compromise his integrity and individuality. So as the Wallses travel across the length and breadth of the United States, they're forced to resort to all kinds of novel money-making ideas to put food on the table and to keep those howling wolves from their trailer door.

Every now and then, Jeannette's mom Rose Mary earns money the old-fashioned way: by working for it. The problem is that her husband takes all the money she earns and wastes it on one crazy, delusional scheme after another. Rex is so fixated on his single-minded obsession of building a glass castle—as he calls his dream home—that he's unable to hold down a steady job for very long. He'd much rather get mixed-up in shady get-rich-quick schemes that hold out the prospect, however remote, of giving him enough money to fulfill his life's ambitions.

But even if Rex didn't pocket all of his wife's money, Rose Mary's attitude to work means that the family would still struggle in any case. For Rose Mary is a bohemian at heart, someone who'd much rather explore her somewhat limited artistic talent than actually go out to work each day, even if her family are desperately short of money. She also shows herself willing to go along with her husband's hare-brained schemes such as trying to make a quick buck out of pool hustling, which almost ends in Jeannette's being raped by an older man that Rex tried to scam.

Rex also uses more legal, but no less crazy, methods of trying to earn a crust. One such method is the Prospector, which is supposed to sort gold nuggets from all the rocks, stones, and gravel. Rex uses his engineering skills to construct the strange device, which he fervently believes will help him discover gold in the hills just like the prospectors of yesteryear and put him on the high road to instant riches (Spoiler alert: it doesn't). For all his extensive knowledge of science, engineering, and math, Rex still only uses what he knows in pursuit of crazed, delusional fantasies that have approximately zero chance of becoming real. And the consequences are tragic indeed. Because for the Walls children, Rex's obsessive pursuit of his life-long dreams has become a living nightmare.