How old are the ducklings? it does sound like she is through, Guess if they aren't fully feathered you'll have to take care of them, I wish I knew why some just give up so soon, I had a couple last year that basically let my gander take over caring for the ducklings,. you just never know.
Some will keep their ducklings up to 6 weeks some much less my mamas so far are usually 4 weeks then it's time to move on. they will still sleep with them at night but pretty much leave them to themselves during the day. after week 4.
Let us know, and don't worry it can take 36 hrs for a duckling to go from internal pip to zip. so patience is the name of the game when hatching. when you candle again you may see the duckling pushing on the membrane trying to break through, if you see that don't mess with the eggs anymore...