New to chickens and need some advice

[ElliesEggs]

We have 2 hens that are RIR (production reds) and 1 is right at 7 months old (that we got as a day old chick) and hasn't started laying yet. The other hen came to us from a different source but was about the same age (long story and 3 rooster later) and has been laying 1 egg everyday since July. She looks healthy and is happy to see us when we go out to the yard. Should I be concerned or just let nature take its course. She is the one on the right in this pix.

And here she is by herself

 

[redfishingirl]

What would you be concerned about specifically? If you think she may be a he, I would suspect HE would be crowing by now.
Some girls just take longer to start laying and aren't as efficient if you are concerned about egglaying.

 

[ElliesEggs]

Just concerned that she has not started laying yet. Possibly something causing it. Maybe her diet or a possible disease. She doesn't even squat when I go to touch her like the other 2 laying hens do. Just a concern there might be something causing it.