Smallest chick in a large brood. Should I separate?

[Finelyfound]

I am brooding 26 5 day old chicks in a heating pad cave in a 3'x4' brooder in the barn. One of the chicks is still about the same size she was day one, the others are now much larger. On day (Wednsday) one this little one looked to have a bit of shell stuck to it's butt, but I let her be. Today it had some dried poop on it's butt and I gently cleaned it with warm water and dried it. I haven't seen as much of this chick because it stays in the cave a lot. I'm worried after having two chicks trampled to death last night and temps of 39 for Sat and Sunday that this one needs some TLC. If I bring her to the house in a box should I bring another chick or two? She was very distressed when I brought her up here alone to clean her up. She doesn't seem lethargic, just small and not really getting in the mix to get at the food.
Thank you
Jocelyn

 

[sourland]

If you bring her inside, bring a couple of other chicks for company.

 

[Finelyfound]

Thank you. I've got a 2x3 cardboard box and a heat lamps, I'll bring the smallest 4 up here until teh nights get above 50 again.