They're forced to work. They're forced to get married. They're pulled out.
I think it's easier to send a little girl to school because there's nothing else you can really do with her. As a girl gets older, she becomes valuable in different ways to her family, and they start to pull her out. It's definitely about work, family. The same thing happens to boys in rural areas, just for different reasons. Boys might be pulled out to work on the farm. Girls might be pulled out to sew or to get married very young.