Mean to hen

2 days ago one of our chickens was attacked by our neighbors dog. She seems to be fine, but is slow and sore from the attack. I have had her in the house for the past two days but felt like she was doing well enough that she would be happier in the coop. We put her in yesterday evening and everything seemed fine. Everyone was on the roosts last night. This morning everyone came out of the coop fine but I noticed that one of the hens kept attacking the hen that was returned to the coop. Ironically its the hurt hens baby but she pecks at her face and fluffs her feathers and attacks her. The hurt hen just cowers down which makes it worse. What can I do to help. I let them all the way out of their run to see if more space will help. The hurt hen just kind of stands by herself and I don't know if it would be better to keep her separated until she is completely better or just keep an eye on them.