Which, yes, I just started. What can I say, maybe I have ADD.
Cankered Roots by G G Vandagriff
I LOVE these books! Cankered Roots is the first in a series-- so far there are 4. Alex and Briggie are professional geneaologists who get themselves into all sorts of trouble when Alex decides to confront her parents about her own family history. (The first 2 books relate to her family history.)
Learn more about the books and the author at http://www.ggvandagriff.com/
These are all quick reads. I read the first 2 yesterday. They are murder mysteries, but they're entirely tame. I wouldn't hesitate to recommend them for a teen or even a preteen that reads a lot.