I can def see life in 2 you probably can see if there is life if the 3rd the fourth doesn't look like anything yet but leave it a few more days it just might be behind. The eggs are around 5-7 day incubated
What your seeing is broody behavior they will protect their egg's nest and ducklings once they hatch. If she is inside a coop with other birds and drakes she needs some privacy I can set up space inside my coop so the other ducks and chickens can't get to her nest or her ducklings once they hatch. Even an xlarge dog crate can work as a safe place for mama and ducklings. Make sure she comes out everyday to eat drink bathe and poop. I don't put food and water close to where they are brooding so they have to come outside daily.