Article continues below advertisementCheryl Hines apparently doesn't hold a candle to Robert F. Kennedy Jr.'s late second wife, Mary Richardson Kennedy."Kennedy spends a lot of time in private conversations comparing Hines unfavorably to Mary," investigative reporter Isabel Vincent wrote in her new new book, RFK Jr.: The Fall and Rise, which hit bookshelves on Tuesday, April 14.An insider told Isabel that he often reflects on Mary's "beauty, her razor-­sharp intellect, her sense of humor, her elegance [and] her grace.