Laura Plimpton died of brain aneurysm
                                
                                
                                    (Newser) -
                                    Martha Stewart's younger sister, Laura Plimpton, died suddenly yesterday at age 59. "She woke up Monday morning at 5:30am, did her one hour of elliptical and treadmill, then showered and felt ill enough to call her husband, Randy, for help," Stewart, 73, says in a statement...