Does she have access to oyster shell all the time for calcium? How old is the hen, and is this something new for her? What do you feed, including all treats, and do they get outside or free range at all? It could be not enough calcium, not enough vitamin D3, or she could have a malfunctioning shell gland.
Yes, she has access to oyster shell and the hen is under 3. We also feed the eggshells back to them. She has been falling short in production little by little over the past 4-6 months. She eats a layer blend of food that I get in the pellet form (full feed), she also get a scratch mix occasionally. They free range 2-4 days a week.