For many people in China, the mid-autumn festival and National Day holiday, falling within days of each other this year, means a week off work and a chance to spend time with friends and family.

But for millions of China's migrant workers, this is a working week like any other.

Many of them have young children back in their villages and do not see them for months or even years on end.

One Beijing organisation, the All China Women's Federation, estimates there are some 58m of these "left behind children".

This is the story of just one girl, Tang Xiaoqian from Anhui province in central China.