I just went back and read what I missed from the part where you found her to here. Please do not use a shock collar!!!!!!
Buy Caeser's books. Get his tapes. Watch him.
Both of the dogs need you to be their benevolent pack leader. You are in charge and calm at all times.
Do not be overly praising of either dog, yet be there to guide them.
Both dogs need to submit to you, but in a very natural way.
I tried one of his methods and I was absolutely amazed. One of the dogs I had, kept after the other dog, who was unhappy about this. Caesers advice in the programs was to put your open hand in the shape of a C and just aim it matter of factly towards the dogs face you want to control and say ksh-ksh. I did this a couple of times with the aggressor and she was laying on her side. I just about fell off my feet. And she didnt get up till I told her she could. I didnt hurt her in any way, but talked to her in dog language like Caeser explained. Really the books and some tapes is the only way to fully understand this. I was just lucky to catch a day of Dog Whisperer specials all day long at a friends house who has cable.
Any violence towards your dog can only traumatize her more. If you dont know what to do I would suggest just some quiet time alone with each dog until you get further councel with the Dog Whisperer, Caeser Millan. They dont need to be pushed together so fast. Give them time to be safe and secure in the same house without having to interact with each other for a while. I am sure Cheyenne is in need of a well deserved rest and relaxation.
Another thng I just thought of is that dogs cant learn anything when they are stressed, so I would give Cheyenne and Zoey a good two weeks to just get relaxed.