The conversation between human and AI assistant.
From the Mortal Instruments series, what is the childhood of Jace and Jonathan?
What were their relationships like with other characters in the series during their childhood?
Jace had a contentious relationship with his pseudo-sister Clary, who was not aware of their true relationship. Meanwhile, Jonathan had a close bond with his biological sister, Clary, before his transformation into Sebastian. He also formed a twisted attachment to Jace, as they were both experimented on by Valentine.