It's rare that a story featuring an adolescent girl is considered a "classic" novel. Sure, there are tons of books that star teenage girls. They get made into television series like Gossip Girl or movie franchises like the Sisterhood of Traveling Pants or The Princess Diaries. There's nothing wrong with any of those shows or movies, of course, but they are certainly considered "girlie" programs and are clearly intended for a female, adolescent audience.
It's unlikely that the Gossip Girl or Princess Diaries novels will ever be considered required reading for any grade level, nor that Scholastic or some other educational publishing house will ever create teacher resources for Teaching the Sisterhood of the Traveling Pants Books. "That's fine. Not all books are designed to be taught in schools or to stand the test of time.
However, several novels featuring adolescent boys are required reading at the high school and even college levels. It's not uncommon at all. The Catcher in the Rye, which features possibly the most unweable teenage male protagonist of all time, Holden Caulfield, is standard in just about any high school English classroom in America.
Just to be clear, this is not an argument that the Gossip Girl or Traveling Pants books are the same level of quality as the Catcher in the Rye. Clearly, JD Salinger was a talented writer and his works do have an important place in the American literary canon. It makes sense that they are taught in schools, and for whatever reason, it seems like reading the story of the almost impossibly smug and immature Holden Caulfield is an important aspect of the traditional American high school educational experience. Great. It's just that, books written about teenage women are generally written for other teenage women to read. For whatever reason, it's uncommon to read a coming-of-age novel about an adolescent American female that's not considered a fluffy or "girly" book.
Sure there's Charlotte Bronte's classic Jane Eyre and the complete works of Jane Austen, which features the plights of young women almost exclusively, but these novels are written in other countries, and other centuries. There's really no female equivalent for The Catcher in the Rye or even The Outsiders. It's almost impossible to imagine a female equivalent of The Outsiders. A novel written about the trials and tribulations of a group of teenage women in that time period would probably have been dismissed as frivolous from the get-go. Reviewers may have called it "Judy Blume in a leather jacket" or something else insultingly dismissive.
Again, this is no criticism of The Outsiders. It's another beautiful book, with far less hate-able adolescent men than The Catcher in the Rye, to boot. The incorporation of Robert Frost's poem "Nothing Gold Can Stay" was truly ingenious, and characters like Pony Boy are the reason this country forces its teenagers to read fiction in the first place. It would just be nice if teenage girls in those high school classes could see more stories about women their age in the required reading.