I think it's implied that she's been partying at the DIKs for a while, much like the other dormies. That friend of hers that you see, the one that is pretty plain-looking? You can actually find her in the first season during the DIK parties. And since they're friends it's safe to conclude that she's either been partying at the DIKs like her friend, or her friend extended the invite to her and the Halloween was the first DIK party she attended. Either way: not really that big of a stretch.
I can see her being interested in MC during the Others route where Derek tries to be a wingman for him and tries to set them up. And since fuckface is pretty good looking not to mention is also the guy in charge of the DIK parties now (bonus if he performed at the concert)...Quite a few women would be interested in him overall. Like Christie, Tara, Tiffani, Felicia, Leanne, Charlotte, Bianca...etc. It's really not that far-fetched that yoga/science girl would be interested in MC given how their interactions go. At least on the surface level type of interest anyway.