12-13 week old layer?

[Paradisewife]

I have 6 pullets from TSC, that should now be 12 weeks old - we picked them up on 3/20:

I actually believe we got what we wantedt; 1 BCM cockerel (crows), 1 Ancona cockerel (crows), 3 barred rock pullets, 2 black sex link pullets, and 1 Buckeye pullet. None have crowed, and the boys started that at least 3 weeks ago. Today I found an egg:
My theory is that one of our 14 older hens (5-7yrs), laid what I call a menopause egg. ??
My other half thinks one of the pullets did it - one of the barred.
If I had to pick one, I'd choose one of the blacks, or none at all. Thanks!

 

[WingItRanch]

None of your pullets look mature enough to lay an egg so I believe you're right and it's from one of your older "menopausal" hens. Older hens slow down but they can lay into their sunset years.

 

[nuthatched]

Nobody is old enough or showing signs of laying.
It may be a fairy egg from an older lady

 

[Paradisewife]

I appreciate the replies so much. Gives me more confidence in my opinions. I've been learning, thanks to everyone here.
All of ours are pets (Therapy Chickens), so we don't routinely cull. I'm often surprised by someone's egg (Stealth layers). Thanks again