The black spots on the Sapphires do not mean anything about their sex. Some Sapphires come out pure white, some come out with black spots, some come out crested and some don't. The Sapphires that I kept to POL were very good layers of large to extra large blue eggs. One kept right on laying through her molt and one stopped laying until her molt was over.That's interesting about the white spots on their heads. I've noticed in the Australorp mixes that have hatched this year that a white spot on the head means male. The two males that hatched 6 weeks ago both had white spots. In this new hatch only one out of 3 have a white spot. So I'll see if it holds true.
I've also noticed over the years that a light colored or buff chick will be female if it has a black spot on it's head. I don't see that on your Sapphires so it may not hold true for Leghorn crosses. I do see some black spots on one's back tho...![]()
Sapphires like their White Leghorn heritage tend to have the cockerels develop noticeable combs at an early age.