Why Did My Hen Not Lay Today? Is She SICK!

by jube
(Kona, HI.)

I have 2 "girls" (hens) that are my pets. They usually lay every day, but today, Dickory didn't give me an egg. Is she ill? Her appetite is great and she seems fine, but why didn't she lay? Can anybody out there tell me if it has happened to them and what, if anything they did.
Thanks so much. I love my girls!
Sincerely, Jube