Question: are clary and jace siblings in the tv show?
Answer: At the end of City of Bones, Valentine Morgenstern, reveals to Clary and Jace that they are siblings, and his children. Jace is not Jonathan Christoper Wayland, as he believed, but Jonathan Christoper Morgenstern. ... She, like Luke and Jocelyn (her mother), believe Jonathan Morgenstern to be dead.