The world divided by Piper

"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...