Action & Adventure, Fantasy, Time Travel, 20th Century 

“Now, I want all of you to try to imagine a world where you could use a machine to go back in time and save lives any time you wanted.” General Mungo said. “How would you change our worlds?” Thirteen year old Shama Katooee hasn't had an easy life: an orphan, she must work and dodge gangs while attending Teleschool with millions of other children in LowCity, DC in 2083. One day her life turns upside down: she meets her best friend, a bird named Deenay, and is mysteriously selected to attend the Chronos Academy in UpCity, where privileged children of GodZillionaires are trained in the practice of Time Watch. Shama learns how to operate a QuanTime machine and how to get along with kids who come from very different backgrounds than her own. While trying to solve the mystery of why she was chosen, Shama is being trained for the ultimate mission: saving her own life. Windows on the World is the first volume of the UpCity Chronicles trilogy. - from Amzon