Wife and i got covid last week, she started getting a scratchy throat and now i believe she has strep, the doctor called her in a prescription for an antibiotic 3 days ago and still showing no signs of improvement?

Strep will respond to antibiotics if the diagnosis is correct. The best verification comes from simple office quick test or culture. Phoned in meds for what may just be a viral process will often fail to result in improvement. Current circulating covid strains are known to cause sore throat/headache/cough/dizziness among other problems. If needed have her seen.