Hooray, I got my first egg .... BUT, obviously, she didn't know where to lay it! The soft shell concerns me. I have free choice oyster shell and grit supplied. I don't know which chicken layed the egg, so I can't supplement to just her. Should I add more calcium to the whole flock? ETA: My chickens are about 17 - 18 weeks old. I think it came from a black sex link, as they have the reddest faces, combs, and waddles.