At the suggestion of her friend Lois, nine-year-old Daisy Green and her younger brother convince their aunt to buy a lottery ticket that turns the Green family into millionaires.
After their family wins the lottery, Daisy and her younger brother Delphie try to find a way to get rid of the people claiming to be relatives and friends who move into the Green's already crowded condo.
When the Green family travels to Washington, D.C., to place some of Mr. Green's sculptures in the White House garden, irrepressible Aunt Ivy decides to use the opportunity to ferret out corruption in the government.
When Aunt Ivy uses part of her share of the lottery money to buy a lake cabin as a weekend retreat, she drags the rest of the Green family into more misadventures.