For those who are interested, I have an update on my Australorp/RIR cross chick . She is now about 6 weeks old and doing just fine. When I moved my birds outside, I discovered some things about their behavior that directly correlated to what I thought was wrong with the problem chick.
From what I can tell, she was too hot in the brooder. The laying on the side with the wing up and leg out, is what all of my other chicks took turns doing under the heat lamp when I moved them into the chilly garage. I was told from a friend that has chickens, that when her birds "sunbathe", they have that same exact behavior.
When she was in the brooder, she didn't want to be separate from the rest of the girls so she would let herself be hot in order to stay with the group. She would just pant and stretch out to deal with it I guess.
It actually surprised me that they didn't need as much heat as I was giving them. I will probably only use a 120 watt bulb next time.
Anyway, she is doing great and is a total sweetheart. I hope this is helpful to anyone that may have similar issues. Thank you to everyone for your help and insight.
Christal
Here is a photo of her now, all the way to the right.
Thank you so much for the update and that she is doing fine. It is helpful to others to realize that she was probably too warm. After having a broody hen raise chicks outside, I have also noted that the chicks only get under the broody for short periods of rest and a warmup. If raising chicks in a brooder, I prefer a large enough brooder to give the chicks a chance to get warm or get back away from the heat. It is interesting that your chick would choose to be overheated just to stay with her flock, LOL. Premier1 sells red brooder lamp bulbs in both 250 and 125, and I prefer the red ones for keeping the chicks calmer and allowing them to sleep at night. Always, though a thermometer should be used to keep track of the temperature in the warmest spot under the brooder.