She may be a I can't recall the word for it but is actually both sexes. I had one like that once. Whole she was growing up "she" had the looks of and acted like a pullet. But when she was grown as in lay kf age she developed tge saddle feathers ons tail " partial" feathers of a chick bird. She never crowed " at least I never heard nor saw her" nor ever laid an egg. I know she was plenty old enough to lay eggs because her hatch mates had started laying. Then one day when she was at about a year old walked out and found her dead.
thank you for this information. I was thinking it might be a late bloomer cockerel but will be watching. if by march I see no eggs/mating I will cull.