3 week old Buff Orp, can you tell if she is a she? Pics of her and her sister

[keller298]

I have two Buff orpingtons. They are just a few days over 3 weeks. Same hatchery and born same day. One has red under her beak, and a larger comb (and is a bit heavier). Can you tell at this age?
Attempting pictures
This is the suspected rooster.

 

[keller298]

Again suspected rooster

 

[keller298]

Full body of suspected rooster

 

[keller298]

Sister

 

[fluffpuffgerbil]

With that comb, those obvious red wattles, and the comparison to your other one(and thinking on my own BO pullet), I'd say your suspected roo definitely LOOKS like it could be a roo...