Female coworker invited me for drinks?

I recently started talking to a girl at my workplace who I kind of have a crush on. Its been about a week and she invited me for some drinks. When i asked who is all going she said two of our other coworkers who are all female but it might just be 3 of us total. She is going to be the DD.

Does this mean anything? I was thinking about inviting some of my male coworkers but then she would have invited them too if she wanted them to join us. I am a bit worried that while she's taking me home she's gonna have me spill my guts out or she might size me up in front of the other females. Would you take this as a sign of interest? As far as i know she's single but we dont really communicate outside of work either.
Female coworker invited me for drinks?
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