BEDFORD, N.Y. - (AP) - Robert F. Kennedy Jr.'s estranged wife, Mary Richardson Kennedy, who had fought drug and alcohol problems, was found dead at the family property Wednesday. An autopsy for the 52-year-old was scheduled for Thursday. No official cause of death has been released. In a statement issued by Robert Kennedy Jr.'s chief of staff, the family said Mary Kennedy "inspired our family with her kindness, her love, her gentle soul and generous spirit. "Mary was a genius at friendship, a tremendously gifted architect and a pioneer and relentless advocate of green design who enhanced her cutting edge, energy efficient creations with exquisite taste and style," the family said. The former Mary Richardson, a longtime connection of the Kennedy clan, married Robert Kennedy Jr., a prominent environmental lawyer and the son of Sen. Robert F. Kennedy and nephew of President John F. Kennedy, in 1994. The couple had four children, the youngest born in July 2001. Robert Kennedy Jr. also has two children from a previous marriage. Mary Kennedy was an architect and designer and had overseen the renovation of the couple's home into an environmentally advanced showpiece. Her family cited her devotion to her children in remembering her. "We deeply regret the death of our beloved sister Mary, whose radiant and creative spirit will be sorely missed by those who loved her," the family said in a statement issued by Lawrence. "Our heart goes out to her children who she loved without reservation."