Was she coughing or sounded congested? I say start adding table scraps, get rid of the pine and use some aspen or pellets. I dont see anything wrong with feeding off sick rats, but not when your ignoring the main problem, It could be a husbandry issue making the myco flare up. I actually dont use any aspen or pellets when I have sick rats. I get them cellsorb (yesterday news) as its nearly dustless and wont aggrivate their sinuses as much as wood product.
You may want to start calling Vets in your area. I called 6 vets before I was recommended to a "small animal/ exotic" breeder that's about 20 minutes away. She's treated rats before and knows what she's doing. The exam was about 35, and the antibiotics I got were another 15$. All in all, my rat is doing great, and hasnt had a flare up since I've been keeping him on cell sorb.