You didn't really express what kind of relationship y'all have right now, so I'm going to assume right now it's strictly just as professional coworkers. 

Short answer, not yet. That's kinda creepy and doesn't often come off well. Can you actively interact with her more? As in "Hey [X], I'm going to pick up some [Y] for lunch. You want anything?". Be polite and professional, and overtime that comfort may grow and you can share numbers. 

Also, do you have any mutual friends? If so, ask if she's seeing anyone and express some interest.