I.G.
There is no need to freak out.
A culture needs a few days, the whole point of a culture is growing out the bacteria taken from your DD's skin. There is no way to make bacteria grow any faster than what they do for a regular culture. They will streak the swab out on a plate, put it in an incubator and let it grow. It takes a day or two plus the time needed to ship the specimen to the lab and evaluate and transmit the results back to the doctor.
I had mentioned on your previous post that a blood draw is not necessary to test for a bacterial skin infection. A culture is the way to go, a biopsy is more invasive and painful and you really don't want to cut into the skin if she indeed has a staph infection... that would just open up a way for the bacteria to get deeper into the tissue. It is something that they will do if there is no infection found to determine what else it may be.
I think you can take a deep breath and try to relax until you get the results. Until then I would just treat your household as if she had staph and start washing and sanitizing... that will give you something to do and will prevent spreading whatever it is to other members of your family.
You can always get a second opinion if you don't trust your doctor, but medically speaking I believe that her approach is standard of care. It is ok for doctors to not identify things like this on sight, especially if the presentation is not exactly typical - a good doctor would order a culture before prescribing strong antibiotics - and that is exactly what was done here.
Good luck!