As of last Monday, the ducks are 14 weeks old. A week from next Monday, the chicks will be 20 weeks old. From my research, those are absolutely the earliest ages at which we can expect them to start laying eggs.
With the heat the way it has been, I don't actually think they'll be laying for a bit yet still. I don't think they'll be doing much of anything besides hugging the blocks of ice we leave out for them or (in the ducks' case) floating in the pool. However, it pays to be prepared, so this weekend Sweet Husband installed three little nest boxes in their coop.
In the next few days, I want to get wooden eggs to put in the nests (supposedly that helps them get the idea), and then...we wait.