Complex sentence: His third wife was Lady Elizabeth McDonnell, the daughter of Lord Alexander Earl of Antrim, they were married in 1777 one of their children was, the novelist, Caroline Henrietta Sheridan in 1779.
Split into simpler sentences: His third wife was Lady Elizabeth McDonnell, the daughter of Lord Alexander Earl of Antrim. They were married in 1777 and one of their children was the novelist, Caroline Henrietta Sheridan in 1779.