i am throwing one for my BFF, and am trying to find a place in DC that isn't Teaism, to throw her a shower for 15 people or so and not spend a gajillion dollars, but she is my BFF, and it is more than likely the only DC shower I will have to host.. so open to places you love. Cocosala and tabard inn are both booked.
Re: speaking of showers...
if it's only 15 people, can you host it at home or the home of another close friend/family member of the Mom-to-be? that would cut down on the cost so much...
or how about renting a room in your community? we have a pool and the HOA rents out the room that's in the pool house - it's only $15/hr.