Double Fudge

Fudge has taken up an obsessive and greedy love for money and his family decides to take him to the Bureau of Engraving and Printing in Washington, D.C. to show how money is made hoping that his obsession would stop there.  That plan doesn't work, and instead they meet up with their long-lost cousins, the Howie Hatchers.  There is Howie, a park ranger who resides in Hawaii and is traveling the country, his pregnant wife Eudora, their twin daughters Flora and Fauna, and last but not least, five-year-old Farley Drexel Hatcher, which is also Fudge's real name.  Peter's family is taken aback when the Howie Hatchers invite themselves to move in with Peter's family for weeks.  

Blume, J. (2002). Double Fudge. New York: Dutton Children's Books.