Hi,
You can kill lice and mites easilly within minutes with 7-Dust...you can find it just about anywhere that has a garden shop(
walmart,
TSC, Ace Hardware) in a red bag. Hold her well and turn her face down so her back is vertical with your stomach. Take some 7-Dust with your fingers and sprinke it at the base of her tail, on and below her vent, and in all of the fluff below her vent working towards her stomach. Then just work it in to the shaft of the feathers. You want to concentrate on this area especially because this is were mites tend to thrive. But to be safe, do the same to rest of her body even you dont see any mites.
If you turn her over and pull back the feathers just under her vent, you will see mites scurrying away (providing she has any). It is not a big deal, but I have seem them, in the thousands, basically suck the life out of the bird. The birds becomes skinny, lethargic, and pale. But as soon as treated, they were back in 2 days. You should 7-Dust her, and the rest of the flock, about once a month to be safe. I noticed that one bird may almost die of mites and the rest of the chickens be completely free of them...??? I dont know how that works, because they spread like wildfire!
Anyways, I wish you luck with her and glad she is feeling better!
Crystalchik