I have 5 zebra hens in a large flight cage together, there are two pairs of CFW girls and their pied mother. One of the girls has been plucking her partners neck feathers lately. This seems to coincide with her egg laying, I think she tries to steal her feathers and arrange them to make a nest (since I don't use nests in my cages). They had been great together for several months now until she started plucking her partner a few weeks ago. So I had moved the injured bird, whose seed sacks I could see in the back of her neck

I don't want to get rid of her because I love her a lot and she is one of the 5 birds hatched in my house. I'm also guessing she learned this behavior from her CFW father since he began plucking her mother when they were chicks. Her father has been paired with the son now instead (normal grey) and all his plucking has stopped. I'm wondering if I can pair the CFW hen with another male from the pet store to stop the behavior, or another female, or even another species. I would rather keep her in her own in a cage to keep other birds from getting plucked, but I know zebras need to be kept with other birds. She has always liked causing trouble, when she was a few weeks old she used to go around and bite everyones toes. Her beak is also a good bit yellower than the other females, could it possibly be a vitamin deficiency? Any thoughts? They eat a diet of balanced seed mix, egg food pellets, hard boiled eggs with shells, spinach, dried fruit and greens.
Please help!
Thanks!