I have 8 chickens, i'm about 25 or more feet away from my neighbor but she claims her son has allergies to my hens. he has never come close to my hens is this even possible? please not that i have their pen closed with chicken wire and then window screen

Unlikely: She likely is allergic to your rooster crowing at 3 AM or the clucking. Anyone can get allergic to anything; Here the symptoms would be like hay fever. He should be tested by an allergist. Check on you town rules with regard to keeping chickens in your neighborhood. perhaps you could place a sound insulator on the side towards her property to help deaden the sound

Possible: And the allergens are more likely from the molds growing in the chicken droppings becoming airborne. Excessive exposure to chicken droppings may potentially induce a condition known as hypersensitivity pneumonitis although this condition is more often linked to pigeons and parakeets (Budgies) when related to fowls.