Check here for posts and my thoughts about touring DC with and without kids!
The National Cathedral
I highly recommend going here and attending. If you have kids their child care and sunday school program is wonderful and I didn't hesitate a second in leaving my children with the staff. We've been several times since and again had a wonderful experience. My kids ask to go that "fun big church" a lot still. Get there with plenty of time to spare and stay afterwards for the tour. We packed a little lunch and ate it in our car.
Military Familiy Free and Discounted Theater Tickets