BA, about 4.5 months. Supposed to be a pullet. It popped wattles and a comb at about 4 weeks, but I wanted to check back in and see what people thought now.
Oh man! I posted a pic of this bird at 4 weeks and 10 people said rooster, no one said pullet. I got another chick to replace it haha but wanted to keep this one until it was definite. Looks like I’ll be keeping her!
One of mine has started to do the squat, so hoping for that first egg in the next couple of weeks. The comb and wattles look about the same as your chick!
Edit: the age doesn't add up. OP said the bird in question was 8 weeks old on June 29th. About three weeks later, the bird can't be 4 and a half months old
Pullet, sometimes Australorp pullets physically mature fast. I have noticed when they do they get the comb/wattles fairly young and then the comb/wattles don’t grow too much more if that makes sense. Unlike a cockerel where the comb/wattles pop up early and just continue to get huge from there. At 4.5 months that looks like a pullet getting ready to lay in the next couple of weeks which would be about right for an Australorp.