Quatie
Free Ranging
The calcium helps their vent muscles to contract and will help of they are having soft shelled. Laying issues is usually a sign there is too little calcium in their diet. Does she has access to layer feed or oyster shells?i opened her bill and gave her half a tums, she seemed to be much more quacking but sounded weird when the quack was finishing if that makes sense. i felt her crop and it was normal nothing hard or abnormal
I would also put her in a bath. It helps with the passing of eggs. Sometimes ducks will go into a pond on their when they are having laying issues.