Sick Chicken Isolation Time?

[CooperChicken]

I've spent the last few days looking after a very, very sick chicken. My chicken Lucy had a lot of fluid in her lungs, wasn't eating or drinking and if I hadn't taken her to the vet she would have died.
The vet said that she needed to have medication for 10 days and to be isolated from the rest of the flock for 2 days.
My question is, why is the isolation time only 2 days, and not until she is no longer sick? She's definitely improved, but I don't want her or my other chickens to get sick.

 

[Eggcessive]

Welcome to BYC. What are her symptoms? Is she sneezing, coughing, gasping, have or wheezes/rattles? What medication are you giving? If it is a respiratory disease, the others may already have been exposed, but it may help to keep her isolated from them. But when they are out of the flock for more than a few days, the others can pick on them when they return. Here is a good link about common diseases including the respiratory ones:
http://edis.ifas.ufl.edu/ps044

 

[CooperChicken]

Welcome to BYC. What are her symptoms? Is she sneezing, coughing, gasping, have or wheezes/rattles? What medication are you giving? If it is a respiratory disease, the others may already have been exposed, but it may help to keep her isolated from them. But when they are out of the flock for more than a few days, the others can pick on them when they return. Here is a good link about common diseases including the respiratory ones:
http://edis.ifas.ufl.edu/ps044

Thank you this site helped me a bunch when I wasn't a member.
She was lethargic, sneezing, making this awful gargling sound while she breathed. Vet said it was basically chicken pneumonia.
I've been giving her Baytril twice a day at the vet's telling.
It's been 4 days after I took her to the vet. She's definitely improved, she's more energetic, breathing is easier and that gargling sound is only on occasion. She also finally made some noise since Monday, sounding very squeaky but she's starting to talk again.
Fighting shouldn't be a problem, the other chickens are very tame pullets. Lucy is about 4-5 years old, don't know the exact age as she's a half-blind rescue.
Thank you for the link!