Even if it was real, that still sounds impossible. Having two gifts is something behind the understanding. Moreover, no one ever had two gifts I'm sure, then what about Jace? Or does Jared have the same shield ability, and his own mind blocking itself from reading and not Jace affecting his brother? Even if it's like this, it doesn't actually change the situation to a better side.
Creation is hard, cheer me up!
Have some idea about my story? Comment it and let me know.