They'll work it out. Think of her as a home schooled kid that has never been around another kid who just met the class clown. He's not doing anything "wrong" it's just overwhelming her right now. Remember, she's never SEEN another duck and may not even know SHE is a duck.I set up a run inside of Lucky's run so they can still see each other. I'm hoping no biting will be going on through the fencing. Yes she has warned me about the mating issue. Im worried but one problem at a time lol before I have a breakdown. You have no idea how bad I felt last night when he nipped her. I'm hoping the noise she made was out of fear and not pain.
Just give her lots of individual attention and treats so she doesn't think she's being replaced, and even if he tries to bite her through the fence, she can walk away.
Even hens will peck at their own chicks to teach them manners, he is likely just trying to be the dominate (as a drake he should be) and she's not reading his signals correctly yet.