Complex sentence: A commoner formally known as Kathleen Jones who is one of the main characters of the trilogy; she appears in book one, but only for a few scenes, and has only a few lines in the entire book.
Split into simpler sentences: A commoner formally known as Kathleen Jones is one of the main characters of the trilogy. Kitty first appears in book one, but only for a few scenes, and has only a few lines in the entire book.