Re Introducing a chick to the group?

[Iheartchickens7]

I had a group of 4 chicks together. 2 boys, 2 girls. They are now almost 7 weeks. About a week and a half ago we lost one. A few days later the remaining girl was looking sick. She was walking around with her eyes closed, puffed up and sleepy. I separated her from the boys and started different medication. By the next afternoon she was back to her normal self.
Now a few days later I decided that since everyone is looking fine, I would put her back with the boys since she was all alone. I put her in and the one could care less that she was back but the other started immediately pecking her and being fresh. He is really going for her eyes and won't let up. She hunched down and submitted to him but he keeps going. After a few minutes she jumped on me and I just put her back in her seprarate quarters.
Now, I realize they have their pecking order but I am wondering when do I interfere? What is the best way of going about re introducing her? I had thought before that maybe she was getting teamed up on by the boys and not actually sick and now I am really wondering if that was the case. She was right next to them in a separate cage. They could see and hear her so I thought all would be ok.
Should I take the fresh boy out for a bit and put her in, and then return him after? Put them somewhere neutral together and then return them? Should I leave them alone and sort it out?

Thanks

 

[sumi]

I'd suggest taking the problematic chick out and putting him in a separate area for awhile. then put him back and if he attacks your chick again, take him out again.
If that doesn't work get a water pistol, put them together again and watch. If he get aggressive give him a little squirt. Aim for his body, not his face. I heard this method works very well.

 

[Iheartchickens7]

Thanks for the reply.
This morning I put her in again and it went much smoother. He is being slightly obnoxious but nothing like yesterday. I keep going to check on them and will separate him for a little bit if needed. Thanks for reminding me about the water bottle. Ours has been in retirement for a while but is now out and ready to go of needed!