I don't know about the kitten pyrethrin.... Have you ever wormed her? Have you wormed the flock? When, how, with what, repeated?
I think ... and, I only think (don't know for sure)... it seems that they shake their head when they have a "runny nose"? Check to see if you see any wet around her nostrils.
Worms can cause a multitude of symptoms, all kinds of things. If you haven't, you might want to worm the flock. Individually, orally, with Valbazen, twice.. you can get all the info you need on these worming and giving oral medications by searching here on BYC.
Good info from dawg53... maybe search "runny nose"... "head shaking"... "Worming with Valbazen"... "Giving oral medications".
I think the Sevin Dust is best for external parasites... clean coop, roosts, nesting boxes, add a little sprinkle of Sevin dust to each of those as well. Now and then for prevention or treatment. If you actually see mites or lice, then treat and repeat in ten days.
Good luck.