Hey, Lisa, I'm Ally and I play three characters here :)
Oliver Wood - Oliver's a nice guy but he's very quiet apart from snappy comments over journals. I'm sure he would get on with Emma just fine, since he's very easy going.
Terence Higgs - Terence just transferred to Falcons, so they'll know each other through that. He's also a quite nice guy so i don't see why they wouldn't get on.
Chris Flint - Chris is also a former Slytherin, couple years ahead, though, but I can see them being friends. Chris is crazy and party's a lot but I can see her being intrigued by Emma's quiet nature.