This sounds great, man. I woiuld ask her when's her birthday, and then follow up with "So, you're still in high school or what?", just to reiterate and get her to follow up if she's 18 or not.
I'm thinking of asking her friend that she works with about her age. To be honest I don't know what to do at this point, since this is at my job the whole thing feels awkward.
why is it so awkward? Do you act like not a normal person at work? Don't flirt with anyone?
Do you not flirt with or hit on girls outside of work?