I have never personally raised them but the pointed feather rule always stands. Cockerels don't switch over automatically to pointed feathers. He will get there. There are even breeds that are "hen-feathered," but a hen will never have pointed feathers (except in rare cases due to hormonal...
At the very base of the tail of your cockerel, there are pointed feathers. It's hard to tell because all feathers are quite glossy, but the shape is the indicator
One is definitely a cockerel, while the other is a pullet so far. Keep an eye out for the pointed saddle feathers that the other is exhibiting-always means cockerel.