lethargic pullet

[L and L]

New chicken person here. I have 8 barred rock pullets, 20 1/2 weeks old. We just started getting eggs this past week, I have 4 eggs so far. Mid-morning today, one pullet was AWOL. I didn't check the coop until after lunch. She was sitting on the roost in the corner. Then she moved to the other side of the coop, still on the roost. I offered her food and water but she didn't take anything. I watched for a bit and she moved to the floor of the coop and scratched a bit in the bedding and sat down. I think she's trying to lay. My question is how long do I leave her alone, before I try to investigate if there's a problem? She moves away from me, so I figure it would be more stressful to try to catch her. She is definitely not 'normal'. I'm hoping that she's working out an egg. Any suggestions on how to proceed from here? I appreciate any advice.

 

[The cheek coop]

Welcome to the flock.
I hope you can get a satisfactory answer. Here is my 2cents worth. Keep an eye on her and make sure she has access to food and water. Also keep a watch on her comb. If it is good and red she is fine.