Amtyl dosage help with 2 week old chicks

[Kairo]

Here's some

 

[Kairo]

I just read that Roosters grow faster. Maybe this is part of it

 

[Wyorp Rock]

It is smaller for sure. Could be a different age or a runt like you mention. If she's eating/drinking, active and not having trouble pooping, then I would just watch her for a while.

You can always weigh her and track her progress to see if she's gaining.

Could be the other is a cockerel...time will tell. I've found chicks a lot of times grow at a different rate but often seem to catch up in due time.