You can try soaking in a warm epsom salts bath.
It's good that she's feeling better. I'm not sure if restricting her mobility is a good idea. How much does she move about as it is?
I'd track her weight for a couple of weeks.
If the other bird is running her off her daily ration, then feed her separately? I know you control how much she eats, but she may not be getting what she needs if the other is eating it up.
I agree, the foot looks swollen. I'd monitor it and see...
She's a meat bird right?
Is she moving about ok?
You may want to start weighing her at least once a week to see if she's losing/gaining. This will help you determine if she's actually losing muscle mass or not.
It's hard to do a comparison from one breed to another.