Welcome To BYC
I'd give her a trim up on the facial/head feathers. It will make it easier for her to see and for you to treat the lice.
Use a Permethrin based poultry dust to dust her all over for the lice. Repeat in 7 days intervals.
I see nits (the white eggs from the lice) near her ears, it may be worth just trimming those feather off if possible. I'd definitely check inside the ears for any lice or infection. Don't forget to dust her TopNot, lice like to hide on the head.
I do see what may be a blocked Nare (Nostril). You may want to check that out. If it's debris, then work on cleaning it out. You can apply a warm compress to see if that helps soften up the material, then use a blunted wooden toothpick or orange stick (wooden cuticle stick) to help remove the material. If it's stubborn and really in there, apply 1 (One) drop Peroxide just to the debris, let it soak in, work on it. Then another 1(drop) of Peroxide, etc. until you get it cleared. This may have to been done over the course of several days, depending on the "patient" Showgirl.
I agree, that looks like it may be a feather cyst. Hard to tell. I'm going to tag in
@Eggcessive to take a look. I'd clean it really well with Chlorhexidine (Hibiclens) or Povidone Iodine. Apply a thin layer of triple antibiotic ointment to the cyst. It's possible it may be a tumor or cancer, but I do see feather follicles on there, so I'm guessing feather cyst.
If you have other photos of her you wish to share those are always welcome. Any concerns about the feet/legs or Scaly Leg Mites?