Well, unfortunately, because we were having nights down into the 20s, it did turn out to be too cold for her duck eggs to mature and hatch. Not so with one chicken egg that someone stuck in among her duck eggs when she wasn't looking.
The result was that one lone chick hatched out and has been thriving ever since under the watchful eye of his/her duck mother.
Yesterday I spotted both Mama and Papa Duck taking a little afternoon siesta with their chickie offspring snuggled in next to his/her very good mother.
Oops, I got too close and woke them up.
It's okay, guys. Close your eyes, go back to your nap and I'll tiptoe away.