Hello, first time chicken owner. We got three chicks in late July (born on July 22 2020) - a lavender orpington, a blue ameracaunna, and a salmon faverolle. The Salmon Fav just started laying last week (yay!). My lavender orpington was generally the most tame and friendly. In the past few weeks, she seems to be puffing up her chest and pecking at me (hard). When the others peck it is out of curiosity, but this seems more protective in nature. Being 7 months, would I know by know if it is for sure a hen and not a rooster? Added a few pics below. If she is still developing, I guess we could see longer tail feathers and spurs, but if not she is maybe just a feisty hen? (Or is there anything else I should be concerned about?)