I genuinely think Regine's original plan in Fright Night Part 2 was this:
Find Charley Brewster
Begin turning Charley's girlfriend, Alex
Thrall/begin turning Charley
Let Charley try (and fail) to save Alex
Fully turn Charley
Somewhere in there, probably after Alex turns, kill Peter Vincent
Why do I think this?
It's unclear what she intended for Peter but it definitely wasn't good. Whatever it was, Charley's fate was supposed to be 'worse' in some way. That could just be turning him into a vampire too, especially considering his trauma with vampires from the first movie. But! I was rewatching today and there's an interest in Alex pretty early on in the film. That could just be because they were hunting on campus, but with Louie (werepire guy) repeatedly trying to woo Alex and Bozworth repeatedly telling him that he's supposed to bite her on the neck, and the way Belle seemed ready to bite Alex on Regine's signal at the final confrontation, I think there was actually a plan to bite both Alex and Charley.
'Cause then she'd get to put Charley through the plot of the first Fright Night again, but have him lose (oof), and turn into a vamp at the end. Possibly even her thrall until she gets bored.
