All the chicks, as you've seen, will be black for both genders. You will have to wait for comb development to determine boys vs. girls, then secondary sex feathers for those who are harder to distinguish. RIR generally telecasts pretty early with combs for boys, so I think that will factor into this mix.
RIR is an excellent breed to increase egg production, and Australorp is also a good laying breed. While considered dual purpose, to a degree, neither will really produce a heavy meat carcass.
You will have excellent layers.
Temperament will depend upon your hen and roo.
RIR has not been my favorite breed, but I've only had hatchery quality. They tend to be noisy and aggressive. Since you've kept a roo, and didn't make complaint about him, I will assume he is a fairly decent fellow as many RIR roo's make it to the soup pot for aggressiveness...but some are really sweet.
Australorps tend to be docile hens, and can go broody, as you've seen with your broody girl (which appears to be your Australorp).
You should have pleasant, excellent layers, hardy birds.
Gender will become clearer around 4 to 6 weeks, with almost certaintly by 8 weeks...except perhaps for a few hold outs which leave you guessing.
My barnyard mixes tend to mature faster, as do most hybrids, so don't be thrown off by a precocious girl.
Congratulations on your new brood.
Lofmc
