Many college have social events, dances, movies, coffee shops, that are open to all students. If she wants, she can attend events of this type. Was the specific dance you mentioned of this type? If that is the case, she would not need an invitation, as a student of the college, she is already invited. Did her friends go as a group or with dates? Maybe that would not be the most comfortable time to start putting oneself forward, but more casual, mixed group events might work. If she she sees or hears something advertised she could suggest to her friends that they go together. Living off campus means she may need to plan more. I guess the questions is, is it important enough to her to put in the effort? I hope she is able to find the level of involvement with which she is comfortable.