Fairy Dust is the only pegasus in the isolated village full of earth ponies. The villagers had no other pegasi before her, but the fact that they have a word for "pony with wings" implies that the village previously had other pegasi, but no longer does. Were they all killed because they tried to fly beyond the wall, too?
After Fairy Dust's execution for trying to go beyond the wall, any pegasus foal born in the village will almost certainly be mistreated simply for being the same type of pony as her. At best, they will be treated with suspicion and doubt from the moment of their birth, because everypony will fear that they, too, will one day try to fly away from Gaea's love. At worst, they might even be killed at birth because their parents don't want to risk them flying away from Gaea. Even if they're allowed to live, what if their parents become so terrified of them flying away that they decide to do something drastic like amputate their wings? After all, if the choice was between waking up every day worrying about their child flying away from Gaea, and taking steps to ensure they could never do so...well, from their point of view, it wouldn't be much of a choice at all.
