My daughter has had numerous staph infections over the years and she has always treated with oral antibiotics as soon as the culture comes back - sometimes before it comes back, because she is so good a gauging when she needs antibiotics.
I know some doctors do not treat staph, I think it depends a lot on the overall condition of the patient, other bugs present, bacteria count and symptoms. My personal opinion would be to treat it - if she is otherwise healthy, the goal should be to get rid of the bacteria overgrowth. I know in some patients who are colonized with psuedomonas, the doctor may choose to not treat the staph because it is believed it helps keep the psuedomonas numbers down.
I believe the reason my daughter always gets antibiotics is because we always see increased sputum and it would be an ugly dark color. It is also the only time she has trouble with a lot of coughing. Since she went for 8 years with undiagnosed CF and lung infections, it was wonderful to actually get the antibiotic and get her cleared up in a couple of weeks - rather than thinking it was "asthma with productive cough" (as we had been told) and having her go months coughing up crappy looking stuff!
If it were me, I'd call the doctor back tomorrow and ask why she isn't starting antibiotics already.