Real baby and childhood pictures of Hilary Duff and Alyson Stoner were used for the "photo albums" of their characters.
When the "Cheaper by the Dozen" movies were made, neither Steve Martin nor Bonnie Hunt, who played the parents of 12 children, had ever had a child in real life. Steve Martin first became a father years later in December 2012, when his wife Anne Stringfield gave birth to his first child, daughter Mary.
Carmen Electra is allergic to dogs. When the Bakers go to the Murtaughs' house, their dog Gunner jumps all over her. When the Bakers are leaving, tiny red dots are all over her body.
The Bakers' cabin for the movie was built and then torn down after filming.
Steve Martin and Eugene Levy appeared in the "Father of the Bride" movies together.