After some months now, we have finally decided that of the 4 white Jersey Giant straight run chicks we ordered from Hoover Hatchery, 1 of them is a hen. Straight run was the only option available for this breed, otherwise we would have ordered 3 hens and 1 rooster, but got just the opposite.
It surprised us a bit how long it took to finally be certain of the gender they look so much alike. The hen has a smaller comb, and her tail is straighter and stands up better than do the roosters. One rooster has much more curl on the tail feathers, the other two not so much, but they do tend to hang down.