I proposed one girl.She said NO.Now she have accept my request on facebook.I still love her.what to do?

About 2-3 months ago I proposed one girl and she said quickly NO to me.Then we see each other only for once in college.Now we are not even in same college.we both changed our college for higher studies.by this time she joined FACEBOOK and now she have accepted my friend request.I am very confused how to interact with her.We were not such as friends in college before.Might I proposed her so early so she said no to me.But now what should I do on FACEBOOK?i want her.....