Ill chicken?

Hi,
I recently posted a thread regarding one of my warren hybrids laying soft eggs/reducing egg production http://chat.allotment-garden.org/index.php?topic=85327.0
Today when I went to let her out she seemed "fluffed up" she was happy to eat some seed I gave her, but there was no trace of an egg again today.
I have just returned to put them both back into their run (they free range for a few hours a day) and she is still fluffed up and not as vocal. I stood with her in their run and she was closing her eyes as she stood. She's not well, but what could be wrong with her?

She may have eaten something that disagreed with her and she'll get better herself. That happened to one of mine.
However she could be going broody....fluffing up and no eggs are 2 signs. You'll know if she won't leave the nest box.
She could be starting to moult.
Keep an eye on her and check she's eating/drinking before you panic then report if there are any new symptoms.