Could you post pictures of where the feathers got pulled out?
Like most Raptors, Goshawks have very sharp talons that enable them to grasp onto their prey easier. Sometimes it can be hard to see, but, if you haven't, give a good look for any small puncture marks. For any open wound areas, I may flush it with some saline/chlorhexidine, and dab an antibacterial ointment, like Neosporin onto it.
As you saw Goshawks are pretty large birds, the largest of the Accipiter family, and also considering the reckless attack style they have, they often catch their prey by surprise, and at a fast rate and can cause serious impact damage. It is not uncommon to have a recently injured hen with dyspnea, but if that kind of behavior continues, it may be best to see a vet.
Keep her warm, and makes sure she's eating/drinking well.
