Please advise regarding a four-year-old bantam frizzled Cochin who laid a beautiful, large egg this morning that had NO membrane or shell. Her shells have been thinner recently (last six or so eggs). Also, I found two lash eggs in the coop early morning in the past 7–10 days (but don't know whose they were). Yesterday morning I found a very thin-shelled egg of hers crushed and partially eaten below the roost bar. No existing or known health issues, and no previous laying issues. In fact, she's been my best layer overall. Flaked oyster shell and grit are available free choice 24/7. They are on organic layer pellets plus fresh daily picked greens and a little bit of scratch and peck (about 3/4 of a cup total for eight bantam hens that includes black oil sunflower seeds, meal worms, small amount of whole organic corn and small amount of organic split peas). Suggestions? Thank you.