My first few eggs from my pullets were away from the nesting box. I had a fake egg in there and they eventually learned to lay in the nesting box even though it took around 2 weeks. Wait another week or so and they should start to lay in the nesting boxes.
This is an Australorp rooster. Even though this is a picture of an older chicken, you can see the differences in this picture compared to your picture. The tail is much curlier and tail feather are much longer. You do have a point because Australorp pullets' tail feathers are much shorter than...
I think she's a hen but another possibility is a slow maturing roo. Wait another 2-3 weeks, she should show some signs of laying if she's a she. Another point is Australorp roosters are much 'fatter' looking than the Australorp in your pic. Also Australorp roosters tails are much bigger and...
First of all, are you sure she is a pullet because this is roo behavior. If you are 100% sure she is a pullet, then this means she must be the top pullet in the pecking order.