Question for all the ladies out there.

Do girls have anything akin to the head nod we guys have with one another? I think about it on occasion, and how nifty it is. It works with nearly every guy, whether you know them or not. It's just the single up or down nod in recognition of the other guy. For myself I notice that I do a down nod as a more polite recognition of someone, like an older gentleman, but an up nod for a more casual 'sup. I just noticed said difference this very evening and am oddly excited about the variations. No idea why. But I'm really not sure about y'all ladies. Do any of you do the nod?