I have one myself, and she had no sign what so ever of a crest. I have never seen little young cochins with such a big crest. They also look like they have a bit of silkie in them. If she's a good breeder she shouldn't mind you asking her, as a breeder you're asked many questions about your chickens.
@Corydg
x2 bantam Cochins do not have crests, ever. They look like Silkie mixes to me as well. And, definitely ask your breeder. You and she may have miscommunicated.
Also, I wouldn't leap to roosters unless someone is crowing, especially the non-barred bird.
On the barred, it is possibly a rooster, but I can't get your photo to enlargen for me. It stays in the small thumbview. The barred also looks to have a walnut or pea type comb, another indicator that is a mix as Cochins have single combs. That also gives evidence of Silkie in the mix.
Cochin roosters will get large red single combs fairly quickly...you generally know by 3 months of age, pretty much without a doubt. EDITED TO ADD: Silkies, and Silkie mixes, can be much harder to sex. Neither bird is screaming roo to me, other than the Barred has a more upright Silkie male type stance...but that is not definitive. If you thought they were male because of the crest, many female birds have crests too. (Cream Crested Legbar for one.)
Below are photos of my bantam Cochin pullets at 3 months of age for comparison.
Last edited: