I would not approach her because of the possible employment ramifications. Are you her manager or just a co-worker? Even if just a co-worker, there might be ramifications. Look - women who are attracted to women are in a minority. Plus, even if she gets attracted to women, she might still not be attracted to you. With those two things taken together - since she herself has not shown signs of interest in you yet - the likelihood that she'd be willing is rather small. Hence, the likelihood that your approaching her would create a situation that would be very awkward (since you have to work together) for her. Who knows what she will do? What if she contacts your HR with a complaint?

I do not know the setting - if it a Mom and Pop store without an HR department, then perhaps... but think through the ramifications.