Okay. So the doctor visit was mostly helpful. Here's what I was told. The rash (because of it's stages), looks like chicken pox--except it's not anywhere on her trunk. It could be hand, foot and mouth--except it's not anywhere in her mouth. We are left with being mostly positive it is an allergic reaction to her penicillin based antibiotic.
The plan: Treat her with a tiny dosage of Benadryl several times a day for the next two days. Change antibiotics immediately to take care of the strep throat. Watch for any worsening of the rash or of other symptoms.
So now we make the changes and wait and see. We have a couple of appointments I'll need to rearrange since I'm going to keep her at home just to be on the safe side. The most frustrating part of this is just not knowing.