When you say you had them in a cage together - what kind of cage? Adult chickens confined to a cage with each other don't do well most of the time. Where there is little space, it's survival of the fittest. One will usually overpower the other due to no space of their own. Whenever you buy new chickens (hens or roosters) that are older than 2 weeks, they should always be kept completely separate from other chickens during their 'quarantine' time unless they grew up together and are 100% used to being with each other since hatch. Place each in their own cage until you're ready to introduce them to your flock. You can keep the cages in close proximity to the other so they have that feeling of not being alone, but not in the same cage.
I would keep doing what you're doing in regard to the *non pain reliever* Neosporin, but I wouldn't put wet paper towels on her sores anymore. Contrary to popular belief, paper towels are loaded with chemicals (to make them safe for human use, go figure) - mainly formaldehyde and dioxin. I'd keep the wound open to the elements for faster healing, but I would definitely keep her separated until she's fully healed and continue to keep an eye on it.
I'm sorry she's going through this.
