First let me just say this before I get started: I'm 17 year old guy who has never dated a girl before, so I don't really know much about girls at all, but I'm willing to help you anyways if you don't mind. Now with that all covered, if messaging her through social media is your only way of getting back in contact with her, I'd say do it soon before its too late. From reading your post its sounds like you really don't have anything to lose anyways so why not? When you first message her though, just catch up with her and ask about how things have been lately with her and what not, and then when you feel its the right time to ask her out then do it. I made a post on here to a little while ago. If you wouldn't mind maybe you could check it out and tell me what you think about my whole little situation that I have going on. Anyways have fun, and good luck man! - MJB360