Why won`t my white cochin lay a egg

[ManOfTheJerseyGiant]

Today my mom was in the pen with the bantam silver pencil cochins. One of the hens jumped between my moms crissed crossed legs and my mom said look little girly I know you aint going to lay an egg. So my mom picked her up and there was an wet just layed egg where the chickens tale feathers was.
But I wonder why my white cochin at least 28 weeks old so why won`t she lay.

 

[Bawkadoodledoo]

is there a possibility for it to be a roo?

 

[BantyChickMom]

Bawk,

man of the jersey giant is my son,
and there is no possibility she is a roo.
We got the pair from a friend at about 4 weeks old, and I don't think she is close to laying any time soon.
Her comb is not red enough or even big enough to indicate laying is near.
She is at least a month older than the other cochins, and even tho we thought she would lay first, I'm just happy I finally have another one laying.

Here's some picks of the white pair and the silver penciled,

These pics were taken the end of November.

 

[Bawkadoodledoo]

they're very pretty boys and girls.