For me the first few times I didn't drink around people I usually drink with were awkward for sure.
I have found that if there is some sort of activity that keeps everyone busy and entertained it really helps keep the focus off of drinking.
Maybe try to keep the visit packed with things to do while she is there; catch a movie, go for a bike ride, museum, sky dive, whatever.
I has gotten easier and less awkward to be around people drinking now that I've filled in the time I would usually spend drinking.
This too shall pass...