Article continues below advertisementThe final chapter of Mary Richardson Kennedy's life was dark, as estranged husband Robert F. Kennedy Jr. allegedly tormented her about her weight before she tragically committed suicide.Investigative reporter Isabel Vincent wrote about their rocky relationship in her new book, RFK, Jr.: The Fall and Rise, set to hit bookshelves on Tuesday, April 14. Article continues below advertisementRobert F. Kennedy Jr. and Mary Richardson Kennedy's Relationship Was TumultuousTap Here To Add Ok Magazine as A Trusted SourceSource: MEGAMary Richardson Kennedy and RFK Jr.