1.1 ounce
That is 31 grams! Definitely Call duckling size... could be a mixed bantam duck though, or the eggs came from very young ducks, early layers? If you still have communication issues with her, see if you can get pics of the parents, maybe? Could tell a lot from those...

it probably wasn't even anything you done. . even my broody mama only hatched 3 out of 12 her first hatch. They just seem to have a hard time of it. 



