Lordy, yes she is!
I'm sure someone will chime in with better advice than I can give. I'm going to follow this thread. I really hope you can figure this out!
Boy, that sounds frustrating! I'm sorry you are dealing with this! I'd be at my wits' end, too.
My chickens have not needed antibiotics so far (knock on wood!), but I know from having a son who is allergic to most antibiotics that knowing exactly what strain you're dealing with helps figure...