When you see her rubbing her beak, likely she's doing it a bit further back on her oil gland. That's how chickens waterproof (to a certain extent) their feathers.
Interestingly, this is also how they convert vitamin D to vitamin D3 (for calcium absorbtion). The vitamin D is in their fats and oils as it's an oil based vitamin. They preen it onto their feathers. Exposure to sunlight converts it to D3. They preen it off their feathers and ingest it! A strange little avian factoid for ya.
Anyway, the oil gland is usually further back. I think she probably overgroomed and now she (and perhaps others) are just pecking at it because it's red, and because it probably itches.
If you could get blu-cote, I'd put some on it to make it less red. That will also serve as an antibiotic coating. Otherwise, continue to use the neosporin instead. It'll heal. You just want to keep watching it daily to make sure no fly finds it.
What is her diet by the way? Maybe there's something there that can help? She's going to need a little protein to help the feathers that were fully plucked to grow back. the ones that were simply broken off at the skin (the follicle still being attached in the skin) will come back during the next molt. So she might be naked back there for a while.