Ours technically has a nursery in the basement, but no one to watch the baby which is what I am assuming that you are asking... H and I just take turns leaving the sanctuary with her to the back of church or downstairs. Church is pretty much a nightmare at this point for us.
St John Neumann in Reston has a great nursey filled with toys and books to keep the kids occupied. Unfortunately, parents have to be in there with their children; there's no one to watch over the kids. The room is attached to the church's cry room, and the audio is piped in to the room. Our kids love it there and always ask to go to "toy church!"
Re: Anyone know of a catholic church in Nova w/a nursery?