In need of advice on when to ask this girl to hang out.

The thing is, I've never talked to this girl at all. All I know about her is that she dated one of my friends for like 2-3 years and they broke up earlier this year -- I don't know why, I don't feel it's my business -- and me and her graduated in the same year. The only way I can communicate with her is by Facebook. I want to go see the last Harry Potter movie in July but I don't know if that's waiting too long. Should I just send her a message tomorrow or something to see if she'd be interested in hanging out sometime?

You've never talked to her? You should probably try that before you ask her out. Just message her on facebook about a common interest.

yup, small talk before asking her out wouldn't hurt

So this girl lives in the same region as you. You can manage to communicate with her on FB. But you've never talked to her. Sounds like you have problems - get off your arse, go and talk to the girl - they don't bite