Titania will have mixed feelings about Brianna, specifically her relationship with Puck. On the one hand, the way those two dated (with all the cheating) was just plain unhealthy, but Puck's as much to blame for it as Brianna. On the other hand, they deserve each other. XD I think she'd be friendly though, if mildly wary about the history of those two. She'll be happy for Brianna having a boyfriend (though she'll still be keeping an eye on her and Puck~) and will ask about New York, if only as a distraction from the carnage. Aaand if something does happen to (re)develop between Brianna and Puck, Titania will probably be the anti-wingwoman coming between them at all the wrong (right) moments and pointing out, "Hey, stop making googly eyes at each other and pay attention to the dinosaur coming up behind you!"
Grant would probably flirt with her a little bit even if he's going to CR for another woman. Just because she's hot. And when I say flirt, I mean he's not actually good at it at all, so he'd probably just be blunt about, "Hey, you're pretty hot. Need someone big and cuddly to snuggle up to?" But he's also gonna get eaten a few days in sooo...
Emmett will be hanging out with Caitlyn probably a lot so it's very likely he'll befriend Brianna at the same time Cait does.
I still need a name for her, but yaass all the "grr screw that guy" stuff!