Does she weigh 1 or closer to 2 pounds? I would go ahead and bump up the Tylan to 1/4 ml per pound 2-3 times per day. No real need to give it by injection, but remove the needle and give it orally. Tylan can cause muscle damage with injections, so oral might be safer.
She may have mycoplasma gallisepticum, or MG which is a chronic respiratory disease. Signs are watery or sticky eye with bubbles and clear nasal drainage. Symptoms can be more severe, especially with secondary infection or disease. It would be good to give some probiotics or a tsp of plain greek yogurt mixed in food daily during and after antibiotics. Here is some reading:
http://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/poultry/FS-1008 Recognizing and Preventing Mycoplasma gallisepticum (MG) Infecti....pdf