My silkie pullet has just started laying. The shells started out very hard and now the 5th and 6th eggs have had very thin, soft shells. The silkie is in with younger pullets (about 2 months old). I would like to put a dish of oyster shells in the coop for the silkie for stronger egg shells. My question: Are the 2 month old pullets too young to eat the oyster shells? Do I have to separate the silkie when I'm putting out oyster shells? Thanks!