ChickenTenderJo,
I hope your babies feel better!
I have 3 pullets in the brooder right now, 2 are about 2 mos (a wellsummer and a production black) and a 1 month old Columbian Wyandotte. The baby always seemed to be a little lethargic, we joked that she might be narcoleptic and considered changing her name to Sleepy from Stevie!
Anyway, she was getting worse, and just like you said, the others weren't snuggling with her, she was always in a corner by herself and she didn't seem to be growing. She got so weak, she would fall asleep instantly in your hand. I was feeding them Purina medicated Start and Grow.
Just when I thought she was a goner, we gave her Pedialite with a dropper. She drank about 10ml. That seemed to make her feel better. I also changed foods. I bought non-medicated starter pellets and ground them down to a powder. She started eating like she'd never seen food before! The others, too. The next day she was on the perch hanging with the others and looked a million times better.
I wonder if that food just didn't agree with her? Were the crumbles too big for her? Or if the Pedialite gave her the boost she needed? (I also added a bit if Pedialite to the waterer. Can't hurt, right?)
Hope this helps and good luck.