So I'm wondering what these 4 turned out to be? Im attempting to try to sex my much younger, in fact much too young to sex sizzles. Its just nice to see these threads updated!
I agree the partridge are girls. The buff looks girlish too, except for the very pink and largish comb, but its a single and they tend to do that earlier than a walnut comb (which is desired on sizzles). You black (which looks blue to me) has the swept back crest my boys get, but sometimes my girls do that too.
Not much help huh? Here's a picture of a couple of my Sizzle chicks around the same age as your chicks (though probably a little younger):
The one on the left was a cockerel, his comb was much bigger earlier and he took longer to feather out. Notice the pullet already has some feathers on her head and little crest starting to pop up. Anyway, the difference in their combs was pretty noticable. But its much harder when you're comparing chicks with different types of combs.