We just went thru hurricane Rita and were without water & lights for 4 days. We got everything back but I did a water change and I treated the water but the city super chlorinated the water and I lost 1/2 of my fish from poisoning. I have one sailfin mollie that is still alive but she is on her side and her gills are red and swollen. Is there anything I can do for her? She is really fighting hard but will she recover or is this permanent damage? I don't want her to suffer if there is no chance for her.

Dont you use dechlorinator as that should neutralise any in the water.
Have you tested the water for ammonia and nitrites as this could be a problem as well.
What other fish do you have? Mollies can take salt which would help with any poisoning of the gills and you can add 2 teaspoons per gallon, but please tell us what other fish are in the tank before you do this.
Add extra air to help.

I treated the water at the normal dosage. The lfs said it wasn't enough. I have 3 gourmis and a pleco

Try and leave a bucket of water out over night and then treat it for the chlorine.
I think you might need to put a post in water chemistry and ask there.
How are the other fish doing? You can add salt at 1 level teaaspoon per gallon to see if that helps.