Crevecoeur??

[Chicken Chicken Love]

I'm 99% sure my chick is a Crevecoeur!! Does anyone have experience with them?? Why my chick is not growing like a large fowl chicken?? Any special things I should know about them, Ex: how to sex them, etc... [ any ideas on sex, the chicks almost 7 weeks old, I know it is probably too young!!]
Pics of my chick below!!

 

[casportpony]

Have you seen this thread?
https://www.backyardchickens.com/threads/chicken-breed-focus-crevecoeur.1109059/#post-17065644