Hello and welcome to BYC! Glad you joined. My family raised ducks when I was a kid. We didn't have a duck house. They just used the abandoned horse barn and came and went as they wanted. None of the females ever bothered the mothers with their ducklings. We even had a very old drake named Barney that would "babysit" and slowly swim around the pond with a huge bunch of ducklings with him as the mothers sun bathed and preened on the shore. When mom was done with her alone time, she'd collect her brood and be off with them.