As Kim says soft shell is a sign of poor calcium in a females body. And could show other signs of poor health.
Hard shell means the female is in good condition health and calcium wise.
Soft shell also means over large eggs can form and cause binding which can have sad results, ending with the death of the female.
Research foods that are rich in calcium.
She also needs good direct sunlight for a few hours a day to help metabolize this.
It is actually thought egg shells are not worth much.
It is better to crush Cuttlebone into a fine powder and sprinkle that over what ever she will eat.
You should have mineral block and cuttlebone available in her cage at all times, and you may find she scrapes at this of her own accord.
If the bird is laying a soft-shelled egg it means she does not have enough calcium in her body to produce a good hard-shelled egg. She needs to be fed better to be able to make good eggs, and if she isn't, she may die because her body will be completely depleted of calcium. She needs eggfood with crushed eggshell in it. The extra protein helps her create good eggs and be able to lay them, and the calcium helps the shell to be properly formed. Give her a cuttlebone to chew on, and make some eggfood by hard-boiling an egg and mashing up the yolk with a little bit of water to make it mushy. Then you crush up the eggshell into tiny bits and mash it up into the eggfood and put it all in her cage so she can eat it.
Birds eggs are soft on the first day, after that they get hard thats the difference of soft and hard...good luck
What does hard and soft shell of budgie egg mean... is hard shell mean fertile egg....?
