We might have a nest of abandoned wild duck eggs. What should we do?

Saturday morning we noticed a female mallard had laid several eggs in our front flower bed (she had been around the bed since last Tuesday). She was there all day Saturday, and yesterday, but has not been seen all day today. Should we worry? We have been out several times to check on her, giving her food (yeah, now I know we should not have), and my husband put out a small thing of water. I am worried that we have driven her away and that the eggs will die........