Complex sentence: In 1861, Amalie learned that her husband had been having an affair, and they separated, she later returned to him, and left again when she was 40 deciding to make a life for herself and her daughter.
Split into simpler sentences: In 1861, Amalie learned that her husband had been having an affair, and they separated. She later returned to him, and left again when she was 40 deciding to make a life for herself and her daughter.