most likely those eggs are dead by now, since she couldnt keep them warm at night. What i would do is start collecting eggs from all the other ducks for up to a week, until you have around 10 eggs, i would then remove the eggs she has under her and move her into the duck house, where you will have to have prepared a clean nest box for her to sit into, with the eggs you collected. With a bit of luck she will start sitting on those. Then all you have to do is give her plenty of food and water, and the hardest thing, wait. After the babies are born just replace all the food in the duck house with the proper feed for the ducklings, until they are ready to switch to the adults' food.