How to talk to this girl?

[O-State]

I know her vaguely, she's a friend of one of my exes but don't worry getting with her wont cause trouble. Any way she broke up with her boyfriend a while ago and so I've waited till I think she should be fine. The thing is I don't see her in person anymore so I will have to do it over facebook but that's awkward for me and I don't know how to do it. Any advice