Explain why the sudden and powerful dust-storm witnessed by the guards enforcing creon’s decree about polynices’ corpse might not have been just a coincidence

Because the gods wanted Antigone to complete the ritual, and so they gave here wind. Remember that this is told through the fates, so the gods must have had something to do with it. And through that, Creon´s decree was unjust so they had to do it.

the narrator is saying that the old lady made her feel uncomfortable. you know this because they say "i found that rather irksome", "perhaps it was her being so upright and trim", and "i don't think it was that, because i thought that quaintly pleasant." hope this !