So I work with a hb 9 that I have been working with for about 5 months, I have always had a gf so I never pursued her. Anyway another girl from work said I should ask her out and even went as far as asking the hb 9 what she thought of me. I asked what she said about me and she was like I think you got a chance with this girl. She seems a little reserved so she was hesitant but not against it.She has been posting things on my facebook wall and commenting on statuses and I do the same. We haven't really escalated things at all though.
I am wondering If I should ask this girl out first or should I get her number and take things from there?
I just don't want things to get awkward at work even though we work different shifts. This just means I haven't had any time to talk to her in person so I am not sure If I should try and get her number on facebook or ask her out that way? seems a little lame to ask someone out over Facebook.

thanks.