Hi momx4plus8!
I just went through this...twice. One died and the other is running around happy as can be. Is yours eating or drinking at all?
I had some electrolytes on hand and hand watered the chicks. The one that lived got attention all night (DD insisted on saving her). Once she figured out how to eat and drink on her own, we let down our guard.
I hand watered the chick that didn't make it, but I think she was too far gone before she made it here.
I couldn't find my droppers, so I just dipped my finger in the water and let the drop of water touch the end of her beak. (With clean hands, of course.)
After that, we offered moistened chick starter. Her pasty bottom has cleared up, thankfully. I was tired of wiping bottoms!