Finally got around to reading YJ #7. Notice Paula Crock telling Sportsmaster (his face isn't shown, but c'mon -- its Sportsmaster) "I lost one daughter, I'm not losing the other" -- the context is that she won't let Artemis become a super-villain. So Paula had a second daughter who now IS a super-villian.
Also, why is Artemis half-Vietnamese? She isn't in the comics. And Paula Crock isn't Vietnamese in the Comics. But you know who IS half-Vietnamese in the comics?
Cheshire.
Also, a notable additional information. Artemis became a Super Hero on her own. It was her decision to separate herself from her Father's plans for her future. This suggests that if Artemis is the person being referred to by the Light as their "inside" source, then she isn't doing so willingly and it is possible that they only THINK she is an inside source for them, since she intentionally thwarted Amazo's attack on the team (again, her own spontaneous decision).