Show up at her dorm room

No point in not being personal at this point. You heft the backpack over her shoulder and start heading toward her dorm room. There was a single large dorm on campus where only the most privileged students got to stay, so that's actually good news; she's probably from a well-off family.

You arrive at the dorm after stopping off for a couple of slices at a local pizza parlor. Swallowing your nervousness, you head up to her room and give a few quick raps on the wood. There is the faint sound of movement, and then you hear a vaguely accented voice from behind the door.

"Can I help you?"

"Actually, I can help you," you reply with a smile. "I found something of yours, and I'd guess you want it back?"

There is a pause, and then the locks slide open. When she opens the door, you see she's currently with no pants, wearing only a purple spandex thong and a white wool belly-shirt. She chews her lip for a moment. "Thanks for bringing it back," she says quietly and reaches out for the bag.