If you're asking whether the episode or the comic came out first, I'm not sure, but...
I have the 1990s Superman Animated Series DVD set and watch the shows semi-regularly with my toddler. I had never heard of Livewire, but watching the episode (this a few months before the recent hype) I did think she was a fun character with some potential. Her name and costume are cool, and in this episode she did have some of the zing of the early 90s Harley.
I like this character better, personally:
+1 RR
Refresh my memory, who is that?
Oh here goes the farm.. Roxy rocket and its also the 3rd appearance of HQ