As we teach our kids about strangers, it's just as important to differentiate between just plain strangers and "safe strangers." Safe strangers are people who can generally always be trusted like police officers, fire fighters, and teachers/principals. Safe strangers usually correspond with safe places. Introduce your child to the idea of safe strangers during daily trips to the grocery store, school, a friend's house, etc.
As you go about your day, point out safe places like the neighborhood fire station, a police station (some communities also have community police posts in each neighborhood), and nearby schools. You can also point out places like the library, a trusted neighbor's house, or local workplace where someone your child knows works. Other nearby safe places may include:
Police and firefighters are some of the most recognizable safe strangers. Because they wear uniforms and drive conspicuous vehicles, kids can easily differentiate them from other people. Teach kids how to recognize and contact (using 911) safe strangers if they need help.
Anytime your child feels threatened, she can go to a safe place. Although some safe places, like police stations, are preferable to others, anyplace that gets the child away from and out of a potentially threatening situation will work. Talk to your child about entering any business or public place if she feels threatened and ask for help from any adult. Most adults can be trusted and will help your child contact you or the police.