I would guess that this chick is around 3 weeks old. It may be a couple days younger or older, but that is just my opinion. They typically take around 2 weeks to get wing and tail feathers.
This bird is still a bit too young to tell the gender, but based on some of the physical characteristics, I think it may be a roo. Though the feather development at a hound age makes me think pullet. Sorry, as I am probably no help, but I think that your bird is just too young to tell the gender for sure.