I was intrigued by this “vintage” Penny Parker mystery book I found at a public library book sale for 50 cents, because I recognized the author–Mildred Wirt–as the true author of the first 25 Nancy Drew mystery novels I so loved to read when I was 11 years old. Nancy Drew books were all written under the name Carolyn Keene, a pseudonym created by the publisher. Many years later, the true identify of the writer was revealed. It was the late 1990s and I was filming my documentary film “Women of Mystery: Three Writers Who Forever Changed Detective Fiction.” I even had the opportunity to meet Mildred Wirt Benson at…