Complex sentence: Feeling a sudden sympathy for him, she asks him about it; he tells her that his son died of pneumonia and his wife committed suicide, and that his time spent with Margaret and her children had been the happiest of his life.
Split into simpler sentences: Feeling a sudden sympathy for him, she asks him about it. He tells her that his son died of pneumonia and his wife committed suicide, and that his time with Margaret and her children had been the happiest of his life.