In a movie you should then seek for contextualizing clues, like if the character hugs her partner/friend, if kiss, if they walk embracing each other, things like that.
Of course, there are cultures and some people that display such signs of affection, being just friends. So again, only watching some more you will know.
As for verbal clues, e.g. one girl could say "my girl friends go out with me on Friday and when we come back we sleep in the faculty/Uni dorm." certainly are her friends, classmates. Whereas, "Mary is my girlfriend" would be needed more clues. "Mary is a girlfriend of mine, since kindergarten times'' suggests they are colleagues since they were kids.
Back to the crux (of the matter): there´s not any difference in pronounce that I know, to make different meanings there.