Chick not growing

[JDfromND]

Hello,
I have a 4/24 hatch date Cochin (LF) that does not seem to be growing. She eats, drinks and poops regularly. I've attached pics of her next to 5/23 hatch date sapphire gems for comparison. Not sure if there is some diagnosable issue here or if I have a Peter Pan chick... Thoughts appreciated!

 

[itspebbl]

Sounds like she is well taken care of. She may just be a runt