I have done enough research on my own, thank you. I've had chickens for over 20 years. I hatch 150+ each year. In that time I have had exactly 2 females that have crowed and both were over 4 years of age. Anything crowing at a young age has been male.
I stand by my opinion that the OP's bird...
Isa Browns are reddish in color with yellow legs. The bird in question is solid buff with white legs. It is an Orpington. At just 8 weeks of age, with that much comb color AND crowing, it is also a cockerel.