Complex sentence: No doubt due to her convict status, in contrast to Balmain's professional position, she was unable to marry him, and she and the children had taken the surname' Henderson, which was Balmain's mother's maiden name.
Split into simpler sentences: No doubt due to her convict status, in contrast to Balmain's professional position, he felt unable to marry her. She and her children had taken the surname' Henderson, which was Balmain's mother's maiden name.