Tylan injectable can be given orally, which is usually easier for most people. The injectable has been known to sometimes cause muscle damage after injections in some animals. Maybe she is getting bruised somehow. Chicken brusiing can be blue, grey, and green. I am glad the swelling has gone down in her wattles. Hopefully the color will become normal again.
You can always check for the pressence of any egg if she ever seems to be eggbound. Insert a clean finger into the vent about 1-2 inches. If she is pooping, then she is not eggbound. Hens can have egg laying problems with shell-less eggs, malformed shells, and other problems. I have never seen a lash egg, but have found lash material when I have done a few necropsies after death. That is a good way to learn about your chickens when you lose one.