Hard to get a good look at the saddle feathers with that moving target, but are they pointed, or rounded?
My cemani breeding project girl (as we don't have legit cemanis in my country and can't import) came to me at POL, so never got to see the awkward grow out phase for her or her brothers, but would assume they follow straight comb standards.
Does he\she have a more prominent feather sheen than your pullets? So far any black feathered boys I've had get their sheen from 4-5 weeks - well ahead of the girls.
I don't like how the tail is feathering in - all the roos in my latest hatch(not cemani) have that 'more development on the outside and less in the center' going on across 2 straight comb breeds. With the comb, my boys tend to have a very prominent upward arch when they start growing in (once again, not cemanis tho). I had an early blooming girl that had me guessing, but it never got the peaky arch the boys did. (This was much much younger too, around 3 weeks).