Thank you for your update.
Did you deworm them already? If not, I would advise to do so as worms make moulting even harder for the chickens and more so, when they struggle with some other not resolved issues.
After deworming you could provide them with a supplement containing Calcium + Vitamin...
How is you hen doing?
In case she still is struggling with crop issues: https://www.backyardchickens.com/articles/how-to-treat-sour-crop-and-impacted-crop-and-how-to-know-which-one-youre-dealing-with.73607/
Maybe she does not ingest enough, some hens just do not like oyster shells.
You could give her some extra calcium +VitD3+VitK for several days to see if this helps.
Is she still laying?
Eating anything in the garden she finds is not an appropriate diet for a laying hen. This will lead to malnutrition which can make her susceptible for diseases and issues related to deficiencies.
Laying unformed eggs without shell can have different reasons:
Lack of proper calcium supplement...