When ducks are new layers they sometimes lay soft-shelled eggs and other odd eggs, so if they disintegrated in the water that may be why. Where she lays her eggs will depend on the routine and set-up you have for your ducks. My ducks have a coop attached to their run that they go into at night. I have nesting boxes in there for them, but they don't always use them. Eggs are easy to find though because it's just their night area I look in. Sometimes randomly they will lay an egg somewhere else during the day, but usually I find them. She also may not lay eggs every day and that's normal. Maybe you've already read about this and have a plan, but one female is not enough for a male. Your female can be over-mated and get hurt. Males typically need at least a few females, so it's good to be aware and watchful to make sure your female is safe and okay, and also have a plan for getting more females ASAP.
