Shooting your shot in public may count as public indecency... and if it gets her, then it's sexual assault, so don't do it 😉
OK, serious answer now... As Anon#2 said, try chatting to her and find out a bit more about her first. She'll probably suspect you're interested in her, and if she's not, then chances are she'll mention a boyfriend or something... Either that, or alter her shift so she's less likely to bump into you, or otherwise try and keep her distance from you.
Personally, in these kind of situations, I would get a rapport going with her. If she doesn't mention a partner herself, I'd steer the conversation towards social things in general, and when appropriate say something like, "Oh, I bet your fella loves that?". If she's got a boyfriend, she'll agree or disagree as appropriate. If she's single, she then has to declare that she's single. Furthermore, if she doesn't immediately follow that up with a story about how great it is to be single or how a boyfriend would be a bad move right now, then you can pretty much take that as a "Green Light".
What's more, if she didn't suspect you were interested before hand, you've also given her the perfect opportunity to "invent" a BF to get rid of you... so she'd almost certainly be OK with you making a move on her.