At the end of 2021, there were 4.77 million left-behind children aged under 16 living in rural areas in China, a 47.4 percent drop from the 9.02 million recorded in 2016, according to statistics from the Ministry of Civil Affairs. The phenomenon is more common in central and western China, where the economy is less developed, forcing many adults to find work in cities.

Taking care of these children requires the support and help of all parties, including the government and nongovernmental organizations, according to Jiang Yongping, a researcher at the Women's Studies Institute of China.

After graduating in 2014, Zhou joined the charity and became its first full-time employee. To help alleviate the teacher shortage in Qianxinan, she and 900-plus volunteers have taught a variety of courses, including English, music and art, in classrooms at 11 primary schools across the prefecture over the past 12 years.