They usually don't mind the small prick. If it's full of hard "pus" or fluid, it can help provide relief. From the color of the growth, it looks like there *might* be some gunk inside. It looks like a couple feathers around have been picked at- possibly hmby her? It's good she's still eating and...
Have you tried lancing it? You can use an 18guage needle and gently poke it to see if anything comes out. If the blood looks "watered down" or there's pus coming from the inside, you'd likely need to open it up and clean it out/start her on some antibiotics. If there's just a drop of normal...