We have (among a few other chickens) two Golden Sex Links that we raised from chicks. At about 20 weeks the first started laying and has been very reliable with an egg everyday. The other started about a week later and all seemed well.. After a few days, her eggs started coming out shell less or not fully developed. Then she just stopped. It has been several weeks and she has no egg laying going on at all. The others are doing well, and we make sure that their diets are proper. She seems happy and normal, but we are worried about her health. Please advise, Thank you.