When I was a young girl (can't remember the exact age but maybe 10?) I loved to read my mother's old detective books. There were two favorites – Trixie Belden and Nancy Drew. Have you heard of either of them? They were fun mysteries and I – at that age – wanted to be just like those gals. I still love to read mystery/detective novels today but they're not the same as good old Trixie and Nancy!!
There were 39 Trixie Belden novels released between 1948 and 1986. Trixie, in the series, is a teenage girl who - with the help of close friends and her brothers - helps to solve mysteries whenever and wherever she can. The characters are adorable and lovable and it's the perfect girl detective series for young girls who love to read and solve mysteries. Read more about this series here Book Fever.
Almost everyone has heard of Nancy Drew, I'm sure of that. She first appeared in 1930 and a total of 175 books were written on this fictional detective until 2003. Nancy was also a teen detective, though older, and often her friends or boyfriend assisted her in solving mysteries. Find a complete list of these books here https://en.wikipedia.org/wiki/List_of_Nancy_Drew_books.
If you have young girls who love to read, introduce them to Trixie Belden and Nancy Drew. They may be "old timers" but it's good, fun and clean reading.