Help, I have 4 pullets - I am not exactly sure how old they are 3 were hatched "mid-march" The Red Star layed 4 eggs small and with a hard shell. Now she sits and no egg. I think the golden laced wydonette (same age) is also laying, her eggs are bigger than the red stars, but the shells are soft and they eggs are always ripped open. The leg horn is not laying yet and she is the same age. I have been reading posts and think I need to stop giving treats to the girls, although a favorite is cheese. Should I be giving then oyster shell?? Any ideas or thoughts?