I am assuming you have a rooster? Chickens will lay eggs without a rooster but in order for them to be fertile and potentially be hatched as chicks you must have a rooster to fertilize the eggs the hen lays. Poultry sex is not very pretty so be prepared (you can avert you eyes if necessary). As for sitting on the eggs, that is a part of a natural process that we humans will never understand. Unless the hen becomes broody (maternal) they will just lay the eggs and leave them for you to have for breakfast. I have read that Australorps do not tend to be a very broody breed (yet other sources say they are exceptional sitters and mothers) so you may never have a hen that becomes broody and sits on the eggs or you may never have eggs because all the hens are busy sitting on nests. If you are sure they are fertilized (you have a rooster that mates with the hens) and you want to hatch eggs you may want to also invest in an incubator.5 eggs in 7 days I am impressed with my young Australorp at least 1 is the layer. I have 4 more that are 2 weeks younger. Cant wait. But I am worried she doesnt sit on the eggs all day will they hatch? Does she know what to do at this early stage?