Keep her mostly on chicken feed and she can have a bit of egg for a treat. Straw can become moldy if there are a lot of damp droppings. Keep it stirred and dry, and add more when needed.
Antibiotics will not help at all if the respiratory problem is a virus, from mold fungus, or environmental. Head shaking is a way to clear the airway and nostrils when there is mucus or fluid being overproduced. If you have a trusted vet, call them to see if they would see your chicken. There...
Videos must be uploaded to YouTube or Vimeo with a link posted here. Look for any nasal or beak drainage/moisture, head shaking, and any bubbles in either eye. Are the dust or ventilation a problem in the coop? I had one hen who ate too fast and would have stridor occasionally.
Welcome to BYC. Is she having stridor or actually wheezing? Do you see any other symptoms, such as swelling of an eyelid, watery/bubbly eyes, nasal drainage, or gasping? Both of those medicines may treat a bacterial disease, such as mycoplasma, but if it is a virus, those have to run their...