Mary Margaret Truman, a singer, actress, radio and TV personality and mystery novelist, died on Jan. 29. Cause of death was not released. She was 83. The only child of former President Harry S. Truman, Margaret published an autobiography in 1956, a book on White House pets and a biography of her father. But she found a huge audience of readers by writing D.C.-based mysteries. Truman was married to journalist Clifton Daniel, who later became managing editor of The New York Times.