The world divided by Piper
(Book)

"Piper Franklin has big plans. First, she'll win the Academic Decathlon with her best friend, Tallulah. Then, she'll finish her life's work: Metaphorical Math. And in the meantime, she and Tallulah will maintain their secret, El Jardin Muerto. Nothing can stop Piper . . . except for puberty. Piper was diagnosed with early-onset puberty, and she's been taking blockers to keep it at bay since she was six years old. But now her doctor thinks it's time for her treatment to end, and Piper's eyes are opened to a completely new world. Piper sees the issues that her older sister and her mom struggle with and gets a very clear picture of her own future -- one that she's not sure she likes. Will a changing body change all of Piper's plans? And why does she have to grow up in the first place? Or does she?"--Amazon.