I went through something very similar to your DD my freshman year of college, so I just thought I'd share. Went to a very large school (10,000+ undergrads) about 3 hours from home after graduating from a small, private hs (120 in my class). One of my roommmates was my bf from hs, and we were also tripled with another girl neither of us had met. From the very beginning, I felt lost and absolutely hated it. I'm a pretty shy person (even moreso then) and just did not want to go out every night like everyone else on my floor. This left me sitting in my room feeling sorry for myself. I never went out and met people, and I still regret that. Instead I just latched on to my friend from hs, and we ended up hating each other. About a month before the semester was over, I ended up moving out of that room and into another one. I transferred to a local college when the semester was over, and have been there ever since. For the first year, I commuted from home, and now I have an apartment with another girl near school.
My advice would be to definitely stick out the semester. You don't want to lose out on time, credits, and money unless you really have to. Don't let her come home every single weekend (I did, and I lost out on so many chances to meet people). Encourage her to just walk around her building and pop her head into any open doors. It's a big first step to make, but you have to remember that everyone else is looking to make friends too. If you do it around dinner time, you're almost guaranteed to find someone who will go eat with you. Looking back, I think its really important to get her away from her best friend so that they're not dependent on each other. Sooner or later, one of them is going to meet a lot of people and will resent the other girl hanging on to her. Lastly, don't forget to write, and get other family members to write and call as well. Nothing cheered me up more than getting cute little care packages from my mom.
I hope everything works out for your daughter, lots of pd to you and her as well.