Difference between just friends and dating
And if you're feeling it, make a move and see what happens.
If they reciprocate then keep the ball rolling as appropriate.
Or, she will just make friends and get to know them in a similar way.
Dating has a much more physical component, there are generally more probing/measuring questions, nuance sexual innuendo... You're more than just two people who know each other. If I'm dating a girl it's because I see qualities in her that I could see myself marrying one day.
I wouldn't expect a friend to take a day off of work to be my dating for a wedding, but if we're actually dating, that's the sort of "girlfriend thing" that you have to do sometimes (or at least try to).