Topic summary
Clary Fray
Extracted from the Wikipedia article List of The Mortal Instruments characters.
Jace Herondale
In City of Bones, Jace lives with his adoptive family, the Lightwoods, and is seen as the brother of the Lightwood children. Later, he is told that he is the son of Valentine and Jocelyn Morgenstern, and not Michael Wayland as he had been told. At this time, he is also told that Clary Fray is his sister. Eventually, it is revealed that he is actually Stephen Herondale and Celine Herondale's son and that Clary is not related to him.