Jessi's Secret Language
by Ann M. Martin & Chan Chau
The graphic novel version of The Baby-Sitters Club (book 12). This series, which started in the 1980s, is in the top five bestselling series of all time for the 9-12 age range.
Also: Karen’s School Picture in The Baby-Sitters Little Sister series, for children in the 7-10 year age range.