Per wiki...
“According to Nicks, the title came from a conversation she had with Tom Petty’s first wife, Jane, about the couple’s first meeting. Jane said they met “at the age of seventeen”, but Jane’s strong Southern accent made it sound like “edge of seventeen” to Nicks. She liked the sound of the phrase so much that she told Jane she would write a song for it and give her credit for the inspiration.[3]”
I remember that.