I totally agree with 99% of what Jay says.
Since she is the sole survivor of of the attack, she
is at the top of the pecking order, and will be, until they are all mature hens, and she is beyond her peak. She shall be the Queen until nature dethrones her. Pecking order is crucial to the survival of a flock (as ugly as it may look to us humans looking in from the outside).
The chicks should be raised near, yet apart from her. Personally, I would look for a part of the coop/run that she has little/no interest in, and put the chix there...if she has no interest in the area, she has less instinct to 'defend' it. The chix will set their own pecking order there...that is important. Once they co-mingle, she will go after the Queen (the strongest) of the new flock to make sure they all know who is
really the Queen. Once she establishes this, they will all accept it. She will have no need to bully the lesser chix in the flock. They will forgo the pain/humiliation, and know who is boss, yet keep their respect for their chosen Queen.
Here is the one little thing I disagree with Jay on: Rather than putting the chix in with her (in her space) for the monitored session, I would put her in with them, in their space. They are already used to their space, so will be less intimidated. She has already shown little interest in it, so will not likely feel that her space is being encroached upon. In my mind's eye, this presents less trauma for all concerned. She will, more easily accept them under these circumstances, and once that has happened, the barrier can come down...after dark, and all are asleep. Once daylight comes, probably nobody will notice that the
fence is gone, and they will all continue 'life as usual'.