It's been a couple of weeks and I thought I would give everyone an update.
A little back story first

I got 10 pullets in the beginning of January that were all between 9-12 weeks of age. 5 Golden sexlinks, 3 Easter Eggers, and 2 Barred Rocks.
The day after my they were delivered I noticed that one of the barred rocks was a little droopy. I chucked it up to relocation stress and kept my eye on her and in about a week she seemed to catch up with the energy level of the others.
If you've read this read you know that about two weeks ago one of my EE's appeared to be lame and had substantial feather loss (which now I attribute completely to being picked on because she was so sedentary). I isolated her and babied her with special food/vitamins, and a round of Tetracyline. She didn't seem to improve but she was eating/drinking/pooping normally so I figured I would give her more time.
About a week ago I noticed that the other two Easter Eggers had runny noses and had started sneezing! I separated them right away and decided to go get some Tylan (thinking that I could also try it on EE #1). I gave them each a 1/2 cc of Tylan via shot in the breast every day for 5 days (they each weigh around 2.5 lbs with EE#1 being about 4 ounces lighter than the other two). The runny noses and sneezing cleared up, and EE#1 started standing up and walking around a LOT more. Her leg lumps have not improved but she seems stronger and more willing and able to forage around the yard (and has even started standing while she sleeps in her crate at night). I AM SO HAPPY THAT SHE IS IMPROVING! She still doesn't have quite the same energy as the other chickens but she is definitely better.
It's funny. I've been keeping her in a dog crate in the house every night for the last two weeks and usually she flies up to the door when the sun starts to set like "Let me in!". Last night we came home after grocery shopping and she was waiting on the back porch. My husband opened the door and she just walked right in to the kitchen and was like "I'm ready for bed". It was super cute and funny.
I'll continue to post back about her progress.