Complex sentence: Janet Norton Lee Bouvier Auchincloss Morris (December 3,1907-July 22,1989) was an American socialite and the mother of United States First Lady Jacqueline Kennedy Onassis; she often stood in for her daughter as hostess for official White House functions.
Split into simpler sentences: Janet Norton Lee Bouvier Auchincloss Morris (December 3,1907-July 22,1989) was an American socialite. Janet often stood in for her daughter Jacqueline as hostess for official White House functions.