Yeah...I would err on the side of caution and forego alcohol. I'm sure you all are classy ladies.
For our rush, we always served sparkling cider in wine glasses on Pref Day, and I liked the way it looked. When I was a PNM, one house served these cocktail-looking drinks...I think it was just fruit punch mixed with 7-Up, but it was really good and they had them in margarita glasses with little umbrellas to go along with their beach theme.