Red Golden Pheasant.... 3weeks old .... just lay's there and won't walk...!

I have 7 Red Golden Pheasant chick's.....and as of 2 day's ago....one just lay's there.... she won't walk...
She is eating and drinking.....but she won't get up....
One leg seem's a bit stronger than the other weaker leg...
I don't know if it's from an injury or what...
The bottom of the cage.....is a great big huge towel....that we change out every day....
There is no swelling, no sore's.... the leg's look perfectly normal.....
Any help would be so appreciated...... !!

 

The leg's work ... =)
Just seems she tries to get up on one leg...but other leg isn't strong enough to pull her all the way up.....