Really, I don't think it matters either way if it's an IOI. If I think it's an IOI, it's an IOI. It doesn't really matter if SHE thinks it is, just if YOU think it is.
If you've known her for two years and you haven't made a move, you're in the friend zone. You would probably have to do a lot in order to create that spark of attraction. And sorry to be harsh, but this sounds like more of a crush than anything.
Lastly, are you sure you want to be touching anyone you work with? I understand that there's going to be attractive ladies that you work with, but I highly recommend just keeping it strictly to flirting. There are already too many horror stories of dating co-workers. Go out and approach other girls closer to your age! Use this awesome forum to learn more about day and night approaches!
Best of luck
