Something that might actually help you find her:
Find out who the RD is for her dorm and ask him if he knows her. It will work best if you go to the RD's room. If it's a guy, he will probably be willing to help you if you tell him the story. If it's a girl, try to feminize the story. If he doesn't know, try going to the RAs in the girls part of the dorm. Well my dorm had girls and boys in the same hall, but in a school as big as your's, it's probably more segregated. Hopefully it's not a 40k student school with 2000 in a giant apartment complex that you call a dorm
Anyway, RDs and RAs have rosters of all the students, and even if it's a common name, there's probably not more than 5 people with that name in the dorm. Go to all their rooms!