If Ivana Trump can write a book, so can Marilyn Quayle. The wife of Vice President Dan Quayle and her sister, Nancy Northcott of Tullahome, Tenn., have written a novel based on a power struggle in Cuba after the death of Fidel Castro. "It delves into the factions that would coalesce in the leadership vacuum," a source told New York magazine. "It talks about what could be one of the great struggles among the powers. It's actually quite a good read." The magazine says the fledgling authors have shown their work, titled "The Rage of the Lamb," to a "very limited" number of publishers so far. Trump recently signed a contract to write two romance novels.