Parvana and her family lived under the Taliban, and the Taliban took her father to jail. So Ms. Weera hatched up a plan for Parvana to disguise as a boy so that she can go to work and earn some money so the family doesn't starve to death.
There are alot of important themes to this story. They are being smart has way more advantages than being powerful, never give up, love conquers all, do what you don't want to if it's for the greater good, respect women, and give human rights.
The story ended by Shauzia moving out and Parvana asks when they will meet again. Shauzia said that Parvana and Shauzia will see each other again 20 years into the future. I think this is a foreshadow of the second and third book.