GIRLS So I told this girl that she's pretty, should I friend her on Facebook?

[pretty girl]

I think with all of these answers your going to just end up doing what you want after all which is a good thing. Personally I think it's very sweet of you to man up and tell her she is pretty. It wouldn't be weird if you added her on Facebook but just try to not come off too desperate you know? Every girl is different. If she likes you she will be happy you did but if she doesn't feel the same way or isn't sure yet then you might just push her away. Maybe try talking to her again and see if she keeps the conversation going and seems to enjoy your company? It's not desperate, creepy, or weird if you add her on Facebook so ignore all of those people telling you it is. It just depends on the type of girl she is and how well things are working out for you
Best of luck!