Well, since this is your 2nd, I'm thinking that you could always decline the luncheon and throw a Meet the Baby party after baby is born. Problem solved.
However, if you do decide to go along with it and the baby is born at the time, I would bring her but wear her. That way people won't be passing her around and such. Also, if you plan to breastfeed, it would be best to bring her with you so you can feed on demand. I know it took me several weeks to establish my supply so being away from my DD even for a few hours was out of the question (at least for me).