Based solely off gut instinct, I voted
They are adorable. My silkies are just now 11 weeks old and I keep staring at them trying to figure out what gender they are! Hopefully the boys will sprout some streamers or something and give me a clue!
I am thinking 1 and 2 are pullets and 3 and 4 are cockerels, basing it off the head poofs, from what I hear silkie pullets have nice and tidy crests and cockerels will have what called streamers sticking up and it wont look so tidy.