As you said 'child free', are you leaving your 2 yr old with someone?? I'd use the excuse that your little one wasn't feeling the best, and you may have to go back to her at any time, and need to keep your wits about you. No one can argue with staying sober for your baby, who might be sick!!! Just add a few, "gee, wish i could drink too, maybe next time" and you should be fine!! Good luck!!