is there some sort of organization on campus that deals with international students? maybe a faculty member involved with something like that might have some insight into whether your roommate is just sort of culturally clueless or just clueless in general, and how to resolve this without offending her.

as for her speaking her language loudly on the phone--she's surrounded by people who speak a foreign language all the time and she has become somewhat accustomed to that. she might not realize how distracting and/or rude that comes off to others.