Some parents just don’t care about their children getting a good education. 

In some countries, the point of a high school education is not to ensure everyone gets the same basic knowledge, but to separate the academically inclined from the not-so-academically inclined and put both groups on paths better suited to their strengths and weaknesses. In a system like this, students who were not as suited to academics might attend vocational schools to train for work, while the academic kids would go on to higher institutions of learning. 

That’s all well and good if you live in a country where a high school diploma is not required for most jobs, but that is not the case in the United States. While some might argue that a high school diploma doesn’t inherently mean that you’re qualified for any number of jobs, it does show that you can show up to the same place every day for four years and complete a long-term goal, and that’s a quality hiring managers desire in their employees. If someone quits high school at age 15, there’s a good chance that they will leave a job as soon as the going gets tough. 

The child in this story wants to learn. She has an innate desire to be educated so that she can thrive as an adult, but her parents have made it extremely difficult for her to do that. They lied to her, telling her they couldn’t afford public school, and because she’s a kid who doesn’t know any better, she believed them.