Cochin Bantam hen having problems

I am new to the breed and purchased two hens from a gentleman about 6 months ago and they seemed to be doing great with my Cochin Bantam rooster. This past week the one hen seems to be acting a little different and this morning it caused concern to me when I let them out of the coop. Now she normally likes to sit in the coop in her normal spot on the top and rest, yet the past couple days she has been sitting in the corner of one of the nesting boxes on the bottom. She has been eating and drinking but this morning she just seemed very lame and was doing this weird thing with her head.( I actually think she was dreaming no joke cause her eyes were closed and when I went to touch her she became startled. I put some food in the nesting box for her to see if she would eat and she kind of just looked at it for a bit. Do Cochin Bantams behave differently then normal chickens at all? I am going to check tonight if she has maybe an egg stuck and go from there. She has fresh water everyday, egg layer and I put oyster shells mixed in the food. She is so adorable and such a good chicken I don't want to see anything happen to her.

Thanks!