Okay, let's see if my brain can come up with anything while still not really awake and rushing around to leave town for a few days...
Seeing as he's been friends with Jon since he was little, and he more than likely knows Jenna as well, it would make sense that Scarlett knows him, considering she's, well, close with Jon and Jenna's her best friend. Though Scarlett does at times lean heavily towards the sarcastic, so who knows if they'll actually get along or not... Scarlett would probably try for Jon's sake.
My Sophomore, Charlie (charlieisabelle), is really in to sports, in particular Soccer and Hockey, so they've at least got that they're team mates to do something with.
I can't think of a single reason he'd have anything to do wih Caitlin (caitlin_carr) right now though. She's quiet and shy for the most part. Jon has taken to bugging her/trying to be her friend since school started again, though so maybe Shawn's doing the same thing? I don't know.
If you think of anything you might want to do with my girls, feel free to let me know. I probably won't be on AIM much the rest of the week but I'll check my email so I'll get the comments! Welcome to Sutton!