My buff Orpington mix (I think) has 5 toes on each foot! Just wanted to share her special-ness not looking for a solve etc.
Actually, five toes in a chicken is not uncommon. There are five breeds of chicken (Faverolle, Dorking, Silkie, Houdan, Sultan) that must have five toes--it is one of their breed characteristics. In other breeds, though, five toes would be considered "mutant." However, since your bird is a mix, I expect that she simply has one of the five breeds I listed above in her background, which results in the five toes.