2 Cochin, can only keep hens. What gender?

[Newbiechick2017]

 

[AlleysChicks]

How old?

 

[Newbiechick2017]

Got them on 5/11, one didn't have any feathers (just down) and the other just had a couple wing feathers. I believe they were 1 and 2 weeks then. So that would make them around 6 and 7 weeks now.

 

[AlleysChicks]

Keep an eye on the bigger one. It is looking rooish with that comb. The little one is looking like a pullet.

 

[Newbiechick2017]

How will I know if it turns out to be a roo? These are my first chicks. I have a Duckwing also but it is definitely a roo. The grey Cochin had a comb way before the Duckwing but the Duckwing grew fast and turned red and already has waddles starting. My other 2 are a Tolbrunt and a Golden Laced and are definitely hens. This grey one is the one I'm confused about since it does have a large comb but it isn't turning red... It does have a shorter and less pronounced tail then the other one though.