Chapter 4, page 23, "He was Mariam's link, her proof that there existed a world at large, beyond the kolba, beyond Gul Daman and Herat too, a world of presidents with unpronounceable names, and trains and museums and soccer, and rockets that orbited the earth and landed on the moon, and , every Thursday, Jalill brought a piece of that world with him to the kolba. "
This quote really shows what Nana is hiding from Mariam because she doesn't get this information from anybody but Jalil. This could provide a reason for Mariam to want to get out of Gul Daman or even away from her mother because she isn't getting the chance to see the rest of the world.