Kirby's after this one *spoilers*
I'm happy about it, I like the character and hope she returns in the future. She could sort of become the new Sidney even. I know it was sort of the plan that she survived, even Wes Craven said he imagined she'd survived, and there was of course the sound in the basement right before Charlie attacked Sidney. And Kirby's last scene, with the question marathon, and Charlie's betrayal, and the last shot of her, all good. Just being clear I'm not dissing it.
But I wonder what could've been if they'd chosen to be more obvious about her survival in this entry. She could've been in the kitchen at the end. And I feel like they should've had her and Charlie be more serious, to make his betrayal greater. They could've temporarily dispatched her sort of how they did Randy in the original, seeming dead for the very end, but then okay. I feel like those changes would give her a greater angle for "My best friend and boyfriend conspired against me". Plus "They planned the finale of my house and I didn't even like Trevor until after he was dead." Of course none of them really seemed all that bothered about Olivia. Randy and Dewey prior (and Chad and Mindy now) had had moments where they were left for dead but turned out to be alive, known before the end of the movie, so I wonder why they chose to take the vague route with her.
What I do find annoying about her survival is that we have to take this to mean that Dewey didn't tell Jill that Kirby was alive (because he had to have known) in the hospital at the end of 4 as being because of privacy laws. Okay Dewey was the Sheriff, not a healthcare worker, so I'm not sure how applicable they would be to him. I know Kirby was still a minor, but her parents were seemingly not there and it was known she and Jill were besties, and he and Jill lived just down the street from each other. I can only assume Kirby was unconscious as well at that point and so couldn't tell Dewey to tell Jill. Which I guess would make Dewey want to tell Jill all the more about Sidney, to give her hope, especially after everything else.
Sorry, got longer than I intended.