+1 on Brassierie Beck and Tabard.
I'd throw Coca Sala in the mix too.

I second the Tabard Inn. Had mine there (upstairs in the beautiful pink and green salon tea room) and it was amazing. We brought in flowers and music and Inn did food, drinks, set-up, service, mimosas, etc. I loved it and heard great things from guests.

Thank you for all the great ideas. To the earlier poster - I would prefer a restaurant but would be open to a cool venue where I could bring in a caterer

Matisse in Tenleytown has a private room. Or Chef Geoff's or maybe Lia's in Friendship Heights (same owner).

Brasserie beck has a private room that can fit 30. Went to an engagement party there and food (brunch) was great.

I've gone to tea for showers at both the Four Seasons and Mayflower. I haven't been in a very long but both were very nice. Yesterday, I went to a brunch party at 1789, which was excellent.

Mine was held at Old Tabard Inn. They have rooms upstairs that can do 30. I think we had 3 tables of 8 and another table definitely could have fit in the room.

Do you want a restaurant or do you want a venue where you will have to do everything (find a caterer, rentals, etc)?

Chef Geoff on New Mexico has a party room.

Any suggestions for a baby shower venue for 30. Thinking brunch or tea. NW DC preferred. Thank you.