Chickens heal amazingly well, and as long as there isn't "heat" or pus in the wound (a great concern with dog bite...the bacteria that enters from the dog's mouth), she looks like it is healing.
Definitely finish your series of antibiotics. I think you can administer Tylan by mouth which might be more effective than water. Be sure to change the water to fresh each day as the antibiotic grows old as the day wears on (but I'm sure you know that being in the medical field).
If she is alert, eating, drinking, pooing normally, and the wound continues to heal without getting "ugly," I think she will do fine.
Now about that dog...obviously some better security is needed for the chickens.
LofMc