One of our wyandottes started laying today her shell is very thin. There has been a lot of stress due to a raccoon got 3 of our chickens in the last few days. I have fixed the coop and ensured their safety even put in higher roosting bars. Our other hens eggs seem fine with a nice shell. should I just start laying out oyster shells or maybe there is another remedy?? Please help we are new to chicken raising. Thanks in advance!