Hi Pat, sorry to hear about your pullet! Usually when a chicken looses the use of her legs it's because of either an injury, a deficiency, or a disease such as Mareks.
Is there any use in her feet? When you put your finger underneath her toes does she grab onto your finger?
If you move her legs does she put up any resistance or seem to be any discomfort or pain? Any swelling or heat in her joints or feet?
You could immediately start her on vitamins in case of deficiency as these won't hurt her at all. If you have human Vitamin B Complex pills you can start her on one quarter pill a day - crush pill on to favourite treat such as cooked egg, plain yoghurt or tuna.
I would also give her some poultry vitamins in her water to give her a boost.
Is there any way she could have injured herself in your currant set up? A roost she could have fallen from or anywhere she may have gotten stuck or wedged?
A video of her trying to move around would really help people here to offer some suggestions!!
Was she vaccinated against Mareks?
She's a real cutie

Hopefully others will be along to offer assistance with more experience than I!