Y'know, I like villains doing a face-turn exactly as much as I like heroes doing a heel-turn: I don't like it at all, unless this change immediately results in that character's last usage, i.e. death.
And Livewire never seemed like a strong enough foe for Supes, either in the mental or physical departments.
This brings up another point for the Superverse villains: are some of (ostensibly) Superman's villains better-suited as primary foes of Supergirl, Steel, Conner, with Superman a secondary target?
I can't find a good Livewire vs Superman fight where one of them doesn't look stupid. But I did somewhat like her appearances on SUPERGIRL and DC SUPER-HERO GIRLS.
I'd say both her and Silver Banshee can go to Kara first, and Kal second.
And the Prankster should a primary foe of Lois Lane.