For this swelling of the eye no I would not separate her.
If she had a prolapsed vent then yes I would separate her. Remember each situation is different but this bird does not look deathly ill so no separating would probably not be the best idea.
If it's easier for you to keep her separated...
I am going to say I do not agree with separating her.
If she is sick your other birds have already been exposed to it.
Stressing birds out makes illness worse.
Separating her will make her more stressed.
The only reason you would need to separate her is if the other birds were beating her up.
Hopefully she just got packed in the face and the swelling is gone in a day or two.
I would pay close attention to see if it's getting larger each day or not.
You either:
A. Do nothing and hope it gets better on its own.
B. Catch her, feel it and make sure there's nothing stuck in her eye or mouth.
The swelling is not normal.
It is possible that she has an infection.
Is a vet visit an option?
Have you brought any new to you birds home in the last few months?
Have you ever had any respiratory like illness in your flock before?