I would like to see some pictures and a video of this hen. @NataleeL , to post a video you need to upload the video to YouTube or Vimeo then post the link here.
I don't know if it was mentioned or not, but you should check her entire body for mites and lice, then treat with permetrin dust or...
According to a few vets, it's not just Safeguard (fenbendazole), it's all wormers in that class of wormer (albendazole, flubendazole , etc).
FWIW, I have used it during molt and haven't seen any feather issues.