Chick that wont grow- month old that looks like a week!

[FFAChickenFan]

I recently had a broody hatch out a clutch of eggs, and we got a nice little bunch of chicks. Three blue/black Ameraucana chicks, and one which I can only guess was a Buff Orphington chick, crossed with my black Ameraucana rooster. That's snowy.

Now.. the other chicks have progressed well, and they are about half the height of my bantams at a month old-normal size.
Snowy doesn't seem like she's grown at all.

She cries constantly, and up until about a week ago she had a problem with a vent that simply would not stop crusting over, although we always made sure it wasn't plugged.
She has normal bowel movements, she seems to eat/drink and although she has sort of a hard time keeping up with the rest of the flock, she acts fairly normal- that is for a week old chick. If you saw her you wouldn't even guess she was from the same clutch as the other chicks. Snowy still has all her downy fluff, other than her wings which have seemed to grow somewhat.
Today,it looks like one of her eyes has shut and wont open. I'm past concerned, although I have no idea what to do with her! Has anyone ever seen this before??

Let me know if you want pics, but theres not much to see. She just looks like a normal 4 or 5 day old chick, except shes a month old.

 

[Granny Hatchet]

although i cant help, i have no idea, i would love to see a picture . hope someone helps soon.

 

[red horse ranch]

Are you sure she didn't come from a bantam egg? Some chicks just fail to thrive. I've had a few that way. Does her beak look normal? I've got a full size hen with a bantam roo and 3 of their chicks have had beak problems. They would be very slow to develop and not live past 3 to 4 months old.
Give her some extra protein treats like scrambled eggs or mealworms. I would like to see a picture of it with it's litter mates.

 

[Jayzandra]

I got a bunch of chicks from the feed store last year and one seemed smaller and slower growing than the rest, even of the same breed. At first we thought maybe we accidentally got a bantam until his feathers came in and he was really scraggly.

It seemed he had a metabolism or digestive problem of some sort as he was ALWAYS eating but was nothing but bones when we culled him, no meat. His crop was always so full it dragged on the ground and was so heavy it made it hard for him to keep his balance.

 

[keesmom]

It sounds like a failure to thrive. There's probably something internal or genetic going on that unfortunately you won't be able to do much about. It just happens sometimes.