I've successfully used "peck no more" to deter birds from plucking their flockmates new feathers. I have blukote as it's referred to here more, but I haven't used it. I didn't use anything until I started to witness plucking.
Like I mentioned, This certainly isn't guaranteed to happen. I was just letting you know it's a possibility. A source on flockmates plucking new feathers?
Edited to add that this could possibly happen whenever the feathers are growing in a very noticeable area. I'm not saying that it's...
It'd probably be a good idea to have some Blu coat or something for feather picking on hand. If she has bald spots, whenever those feathers start growing back in, oftentimes (although not always) flockmates will pluck and eat the feathers as they break through the skin. You'll want to camouflage...