I have three 6-wk-old "layer" chickens
I'm hoping that what you meant first days of August, so you really mean 6 week.
They hatched within the first 4 days of September
I agree - and one of the things I think these birds need right away is some exercise. What are the CornishCross contained in? The layers are smaller but more mobile - can they go join the meat birds for a couple hours a day at least?
I feel a HIGH degree of responsibility for animal care!