I am new to chicken keeping and I have 4 hens, 1 Rhodbar, 1 Plymouth barred rock & 2 cream crested legbars that are almost 6 months old. The rhode and Plymouth have been laying everyday for about a month. One of the cream crested started to lay this past Saturday. The first egg was crushed & the shell is very soft. She laid another egg this morning and has a small hole where she pecked at it and shell is soft. I feed a Layer formula, mix in oyster shells & free feed crushed egg shells once a week. Is this normal in a young pullet in this breed?