Anecdotally, I had two female coworkers that acted the same way around me, kinda flirty but in a more friendly way, I felt, rather than trying to hint at anything. One said "EWW" out loud when someone suggested we date, and the other told me way after the fact that she was super in to me and I should have made a move.

The women I've actually dated made an effort to make sure our feelings were not only known, but reciprocated before laying down the "rizz" too much. I have no problem lightly flirting with someone that has no desire for a relationship, its fun, but that can't be the only sign you're in to someone when it isn't even REALLY a sign for a lot of people.