Cao once worked in a public kindergarten. However, she quit the job and opened a private kindergarten for children of migrant workers who could not afford the public kindergarten.

Cao Xiuhui and her colleague teach children to dance on May 22. [Photo/Xinhua]

Cao Xiuhui puts shoes in bags made of discarded cloth on May 22. [Photo/Xinhua]

At the beginning in 2001, Cao was the headmaster and the only teacher in the kindergarten. To maintain the operation of the kindergarten, Cao had to try her best to save money.

"The shortage of funds poses a major obstacle; we could not afford new desks,” Cao said. “Sometimes I want to give up, but when I heard them calling me ‘Mother Cao,’ I feel encouraged and full of energy to face the difficulties.”