They have plenty of space with a tree stump and 2 perches. We also have bark covering the floor in their run so they have something to scratch around in. We have 2 grit and oyster shell containers around the run so it is not just in their food. We also have a mirror so that keeps them occupied...
We have decided not to put her on the perches now. We are leaving her in isolation until her feathers start to open. We have 6 hens and we feed them on Barts Garden Mix as they are just backyard chickens. The feed includes things like layers pellets, dryed sweetcorn and peas, oyster shell etc.
I have the same problem with my molting hen. The pecking got to the point where my hens pulled her quills out and caused her to bleed. We have isolated her from the other flock for a day and a bit now, we have sprayed her with purple wound spray to try and deter the redness that is attracting...