I would treat it like you would yourself. She will more than likely need antibiotics to knock the infection out of her. I dont think that I would lance it. Let her immune system do the work with the help of the antibiotics. Your farm store should have what you will need.
Sounds like infectious bronchitis, common cold. Add vitamins/electrolytes to the drinking water and probiotics. I just went through this, got infected chicks from rural king, spread through my flock like wild fire. They recover rather quickly.
I used to live on a shared roadway....never again. Ask him if he would like you to speed up when you see their pets or...him. Really shared things like drives and wells etc. never works out. Can you unshare the drive? Relocate yours to a different place.
I am not very happy right now. I bought 30 chicks and 3 turkeys from the rural king. The first day home I noticed 2 sneezing. Now (6 days later) many are sneezing, and 1 died who was one of the first to sneeze. Its little throat was full of mucus. I think that they have infectious...
Have you considered a hoop structure like joel salitin uses? They are cheaper than a steel building. Here is one that they use, he has a ton of stuff on line.http://polyfacehenhouse.com/2012/07/hoop-house-5/
Having the water in the coop creates humidity which creates frostbite. I keep the water in the run. Put some neosporin on it and put the water out, that should help. My roo still got a touch of frost bite even doing these things. Also make sure there is good ventilation so humidity can't build...
You may want to put some stones or rocks in in so if they fall in they can get back out. I can't tell how deep it is, but I would worry about them drowning. Can you clean it easily? Looks pretty neat, my ducks would love it!
I really don't give mine food scraps. I give that to the hens if I have it. I guess for a treat for the chicks, I mix a bit of water with their crumbles and give them like a warm cereal. They love it. I also put a bit of alfalfa hay in so the can scratch around and have something else to do.