Could this be accurate to say to her....?

so say you know this girl whom you never spoke to before but she has seen you around before....and she has accepted your friend request on facebook one day....would it be a bad idea to send her a message explaining to her who you are and that you thought she was very pretty but didn't have the nerve to talk to her when you did see her?( you would say other things but that would be the gist of it) fact being that facebook would be the only one possible of contacting her. ( if all this was said in a completly non wierd and creepy manner)....other fact being you are both 21...and not to mention that her statuses are mostly about her not finding a guy....so you know for a fact that shes single