Getting in touch with a girl

So I was in this art program over the summer. For a couple of days in the program the group that I was in combined with another group. There was this girl in the other group, and I noticed that she kept looking over at me. I never got a chance to talk to her. And I don't mean that I didn't talk to her because I was nervous, I really never had the chance. Would I have talked to her if I did have the chance? Probably not. But anyway, the program is over now. I have some friends who are friends with her and have her phone number. I really want to get in touch with her but I don't want to come off as creepy. Should I look her up on Facebook? Or ask a friend for her number, and if so should I text or call? Or should I just wait for our paths to cross again? And most importantly, what should I say?