Sorry for the long post, I have 4 ducks and 1 drake about 5-6 months old. They were all raised together and have gotten along pretty well up until recently. One female is a white crested and a 2-3 weeks ago her crest started getting shorter and eventually got a bald spot. I separated her from the other ducks where she could still see them. She healed up well so I put her with the other ducks and put the male in the separate pen by himself for about 9 hours. When I came home I checked on them and her crest was being pulled out again
so now she is back in the pen by herself. I think it’s my female khaki campbell, I have seen her mount the crested and pull at her head. None of the other ducks have any balding on them.
Is my poor crested duck doomed to live in a separate pen forever? Will the others eventually lose interest in her? Should I try to isolate the khaki campbell once the crested is all healed up again and see if they leave her alone? Would adding more ducks help since it seems to also be the female picking on her as well?
Thank you all in advance for any help

Is my poor crested duck doomed to live in a separate pen forever? Will the others eventually lose interest in her? Should I try to isolate the khaki campbell once the crested is all healed up again and see if they leave her alone? Would adding more ducks help since it seems to also be the female picking on her as well?
Thank you all in advance for any help