Besides the permethrin, were there any other ingredients listed?
Permethrins are found in quite a few products used topically on dogs. They have a fairly wide margin of safety, unless the concentration is very high. If you think Heidi really only got those few licks in, I think it would be fine to just monitor her at this point.
If she had consumed a large amount, then giving activated charcoal (at an emergency vet) would be good, but often treatment is just given to control any clinical signs of permethrin toxicity.
Signs to watch for include: Depression, increased salivation, hyperexcitability, muscle tremors, vomiting, diarrhea, walking like she's drunk, and inappetance. are commonly seen. Other signs are elevated body temperature or low body temperature, weakness, seizures, and difficulty breathing. In most cases signs are mild and respond to simple therapeutic procedures. Recovery usually occurs in twenty four hours.