Porn for Adolescent Girls...
Really, people always say that girls that age read Nancy Drew, Babysitters Club, Sweet Valley Twins, or if they're tom boys, R.L. Stine books or the Hardy Boys. Nuh-uh. While I dabbled in those other series/authors, I was addicted to V.C. Andrews by the 7th grade and still now & then read them and think back fondly on those books.
The protagonists are usually girls, between the ages of 12 and 22 (they do get older as the series goes on) who have some of the most traumatizing childhoods, ranging from living an extreme poverty and being sold by her father to being locked in an attic with her 2 brothers and a sister for years by your mother & grandmother. Often, these circumstances lead to incest, pseudo-incest (stepfather-daughter), sexual abuse or unintended incest (she didn't know he was her uncle at the time.)
These are the books that probably 25% of middle class middle or high school aged girls have read and are a huge cultural force, and have probably inspired many lifetime movies. It would be awesome to do a study on their impact.
Also, Judy Bloom (yes the same woman who wrote fudge) wrote a few novels in this vain that I read in the 8th grade.