Rooster confusion

[Chicks Creek]

Hi all. This is a multi part post so please bear with me.

Background: my sister and I bought sapphire gems from the same store (country max) 2 weeks apart. I posted a few photos of her one chicken on the BYC fb because at 8 weeks (s)he had a very red comb and waddle. The resounding consensus was that the bird was a roo. Most people especially pointed out the rust colored feathers on the chest.

I had one I thought was a roo because of tail feathers and body shape. Fast forward to now, mine are 8 weeks. The one I thought was a roo looks like a hen now but one of the others who looked very hen-like to me, body and tail feathers wise, is getting very red. I also recently read that sapphires are sex linked.

So now I'm confused about my chickens and also my sister's.
Is it normal for sapphire gems to get rust colored feathers?
Are they, in fact, sex linked?
And if so HOW do we both end up with roos from the same hatchery at different times?

I'll post pictures in the comments

 

[Chicks Creek]

Is this a head dot?

 

[sourland]

Is this a head dot?

NO.

 

[Chicks Creek]

Raspberry, who I originally thought was a roo. (On the right in the pic of the 2)

 

[Chicks Creek]

The darker one I thought was a roo for a hot minute. The one to the back left is now getting red comb + waddles

 

[Chicks Creek]

My sister's.

 

[talkinboutchickens]

That bigger one is def a roo (what caught my eye was the feathering, the legs, and overall size of the bird. Comb and wattles aren't as accurate with sapphire gems IME bc females have large combs and wattles anyway.) However, the smaller one can def be a female.
I am in fact confused about how he did not have a head spot or any white coloring, usually the males always do. Therefore, I am questioning if these guys are actual sapphire gems (perhaps the sexlink thing doesn't always do it's job?) Not sure about the gold/reddish leakage. I'm sure some SG's have it but it may not always come through in some birds. I am just guessing here, I don't know anything about genetics and such