There are 4 books in the Seven Sister Mysteries series.
The Seven Sister Mysteries series does not have a new book coming out soon. The latest book, Trouble in Paradise (Book 4), was published in August 2002.
The first book in the Seven Sister Mysteries series, The Secret in the Attic, was published in August 2002.
The Seven Sister Mysteries series primarily falls into the Mystery genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.