She probably is still showing symptoms since the dosage was a little over twice as potent as it should have been. Also, she may have gotten more than the usual 15 ml/1/2 ounce that is sprayed on. In the future, I would use the permethrin garden dust. I think she probably will recover over more time. Do you have a dust bath for her? It might help to help her dust bathe and it may help to wear off some of the residue. Permethrin overdosage does cause neurological problems as well as other more serious respiratory issues, but the exposure through the skin is usually less dangerous. Here is some reading:
https://www.ncbi.nlm.nih.gov/books/NBK231556/
https://www.ncbi.nlm.nih.gov/books/NBK231556/