Did you bump it up yet...would go ahead and do that. whamp thought of a good idea..go put some other eggs out where she had them, see if she returns by morning. Then watch her, if she stays, you could put them back if you want.I don't know ducks. Do they accept babies at the time they should be hatching? Could you sneak out the babies when they are strong? Ducks??
I just did that with my ancona. She was a pretty bad broody, and liked to leave the nest for 6-7 hours at a time. As soon as my saxony started hatching I snuck them out and swapped for her eggs. That was 4 days ago and so far she's an awesome mom. Her eggs are now cooking in the incubator.