It sounds like she is too hot. Plastic bins for brooders frequently get too hot.
Please post a picture of your set up. When you say you lowered the light does that mean you physically lowered it or you actually raised it to lower the temperature?
You need to hydrate her. Put a drop of water on...
I have one baby chick 6 days old that we hatched in an incubator in my laundry room. Then we created a brooder with a plastic bin, light, water and food. She has been doing fine until this morning when she is very lethargic, stumbling, falling, wings spread out as she is lying there. I...