Thin shell from only one bird

[Cateydid]

One of my 5 chickens lays a thin shelled egg every time. It's pale and often breaks when collected. They are are all 1-2.5 years old and have the same organic diet of feed supplemented with leafy greens, vegetable peelings and crushed egg shell.
Thoughts?

 

[Mountain Peeps]

This link will hopefully help...
https://www.backyardchickens.com/a/common-egg-quality-problems

 

[Cateydid]

Thanks but I was talking to a farmer today who believes my one chantecler is much older than I was led to believe 9 months ago. The eggs are smaller and vey pale when compared to her "sister". I'm not concerned about their diet and the idea of them being stressed is laughable! Great article though so thanks again