Who is Jocelyn Fray from City of Bones and what is their importance?

Jocelyn Fray is Clary's mother. Once married to Valentine, she quickly left there marraige upon finding out that her husband was experimenting on their children by injecting them with demonblood. Jocelyn takes Clary and runs to New York. When Valentine (her husband) returns, she has places herself in a continual coma. She is the only one that truly knows where the mortal cup is hidden in Idris.