I went through something similar in college.
Tell your daughter to try to spend time with her roomie, and see if they can't get involved in something together. (Like Student Government or an organization supporting a common interest.) That may help her roomie to see that she still wants to bond and be friends!
I wish the best for your daughter, her new wonderful Pi Phi sisters, and her roommate.
__________________
“All his life he tried to be a good person. Many times, however, he failed.
For after all, he was only human. He wasn't a dog.”
― Charles M. Schultz
Warning: The above post may be dripping in sarcasm and full of smartassedness.