Here’s my theory: Hillary Duff has either started snorting crack on a regular basis or throwing up between meals. Duff stars in ‘Cheaper by the Dozen 2,’ the sequel to 2003’s ‘Cheaper by the Dozen,’ which Hollywood producers apparently think ended in a cliffhanger rivaling that of finding out Darth Vader is Luke Skywalker’s father in ‘The Empire Strikes Back.’ Expect to see a washed-up Steve Martin, a multitude of childhood actors and tons of vomit spewing forth from the emaciated Duff.