Hi, there!
Just checking into see how your bird is doing. Updates to these threads are very useful for people in the future experiencing the same problem.
If these are wild ducklings they should be turned over to your local wildlife rehabilitator, if you are unable to find one you can try contacting your local game warden.
Looks pretty minor to me, dabbing a bit of Neosporin around the affected area should be sufficient, bill injuries usally recover fine. The pink part on the tip of the bill is normal with Wood Ducklings, that's not an infection .