E.M.
The zoo, aquarium, an art museum, a botanical garden. If she is adventurous maybe an amusement park or even something like miniature golf or other kid theme that you turn into kitchy-chic. If she is young, likes (liked) to go out to clubs, maybe even a night club that will work with you on some great mocktails, get the whole crowd involved in baby games. If she is a bookworm, do it at a great local bookstore and have everyone bring their childhood favorite book, do a children's book themed scavenger hunt, have tea and snacks with a literary theme. If she is into gardening, maybe a local garden center or florist, have everyone work on decorating and filling a planter or hanging decorations on a young tree to plant in their yard when the baby is born.