It may have been her big sister, Britney Spears, who sang, "I'm not that innocent," but it was Jamie Lynn who really lived those words. In December 2007, the 16-year-old "Zoey 101" star announced that she was pregnant with her longtime boyfriend Casey Aldridge's child. "I didn't believe it because Jamie Lynn's always been so conscientious," her mother, Lynne Spears, told OK! "She's never late for her curfew. I was in shock. I mean, this is my 16-year-old baby." Yeah, her baby was having a baby.