Is there a problem with her crop??

Im very new to this so to all you experts i may just be over worrying lol ::)Ive noticed that one of my girls seems to adjust her crop alot in the late afternoon. its never in the morning its when i go down to give them there corn etc in the late afternoon. She still eating,drinking,laying and doing all other chickeny things and looks wise she is very healthy. She does eat the grit also. Is this normal or should i be worried??

I did think that its just i notice her doing it more than the others. I just checked her crop when i put them to bed and it was hard and felt the same as the others. Thanks joyfull