1 looks like it could be a roo, but may be a hen, (and one of the fanciest chicks I've ever seen btw with those beautiful leg feathers). 2 looks to be a hen for sure. 3 looks like a rooster, but a pic of the front focused on the comb would be helpful to be sure. 4 looks like a roo, more certain than 1, less certain than 3. You've probably got at least 2 roos, maybe 3, and one pullet for sure.
#1 if bright yellow feet, Bantam Cochin, male, definitely male at 4 weeks with that much comb
#2 Is that a single comb? Lots of possibilities with that growth pattern. Might be an Australorp. Looks to be pullet. Need more development to ascertain breed. Come back when adult feathers are in.
#3 is a Silver Laced Wyandotte (if that is indeed a rose comb) pullet