Thank you for your help but Penny just passed. We do not believe it was Mareks because it has been too long since she first showed symptoms and none of our other chickens are showing symptoms and are acting fine. Thank you again for your help.
So very sorry to hear that she didn't make it. For the sake of the other pullets, you would still be well advised to create a bachelor pad. If she was the favourite, there will be a new girl put in that position now and it is not a healthy environment for young pullets to be in.
I hope this is an isolated incident and good luck with the rest of your flock.
Sorry to hear of this. It could be Marek's but I think it's more likely that the eagle is what killed her-- an eagle's talons can do a lot of damage that isn't readily apparent by sight and such damage can kill a chicken slowly as has happened here. She also could have died from the stress and shock of the attack.