Hey, we managed to fix the issue eventually but took a long time! Our Hens have a built run with their coop and then there is a built section for them to free range, avian flu lockdown came round and meant that they all had to be under cover which made it hard with a bullied chicken, as she was living separately. We created a covered space for her outside of the run which only had chicken wire seperating her between the other hens so theh still lived alongside each other bit couldnt get to each other. They lived like this for about 4 months, I was also too contemplating getting some new hens for babs (bullied hen) but was worried incase it caused more problems. In December time we slowly started tl introduce babs again, we started using distraction treats so the other girls didn't notice she was there, it was a slow process and we built up supervised time each day to ensure she wouldnt be fully attacked. Over time of doing this they gradually accepted her again, there were some tiffs and fights but nothing terrible and its was more to sort out the pecking order. I forgot to add that we started putting her in the coop with the other hens at nigbt as the weather was getting really cold, and in the morning we took her out and Seperated her during the day, my hens dont fight in the coop so thoufht it was a good time for bonding etc. Now babs lives with them and she still get chased on the odd occasion and pecked but doesnt seem to phase her anymore. I still do seperate treat bowl for her hidden away from the others so she has an equal chance of getting treats but it was a long process. This all started in August last year and they have only started to accept each other about 3 weels ago. Good luck with yours and what you decide to do xxx