Complex sentence: Cornwallis-West's sister, née Mary Theresa Cornwallis-West, was a noted society beauty and the first wife of HSH Hans Heinrich XV, Prince of Pless.
Split into simpler sentences: Cornwallis-West's sister, née Mary Theresa Cornwallis-West, was a noted society beauty. Known as Daisy, Princess of Pless, she was the first wife of HSH Hans Heinrich XV, Prince of Pless.