A little hard to tell exactly what's going on in our boxes. Both the swallow and the wren are sitting on their nests. But, I can't get a good look to see how many eggs they've got.
Mrs. Swallow has imported a number of feathers into the box. The last time we could see the eggs, there were four. Swallows usually lay five to seven, so your guess is as good as anyone's.
Mrs. Wren has her eggs in the cup in the back of the box. The shadows are too deep to see the eggs.