Thin 19 week old hen

[AbiandAmi]

Hello
I have 2 chickens that are now 19 weeks old (not yet laying)
My brown chicken is probably twice the weight of my white one and i am wondering if this is normal?
They both seem healthy, they seem to eat well and poos are healthy looking.
I have noticed the white one eats of the ground alot more and the brown one prefers the feed from their bowls.
Is it anything to worry about that one is so much thinner?

 

[Percheron chick]

What breeds are they? Sounds like the white one is a layer (smaller bodied, better layers, excellent feed conversion) and the brown one is probably a dual purpose (OK layer, OK meat bird, not superior at either)

 

[AbiandAmi]

Sorry I only just saw this reply. I actually have no idea what breeds they are
I can post some pictures when I get home, maybe you can tell what they are?