Zheng Zhongyan poses for a photo in her study. [Photo/jiaodong.net]

When asked whether her 30 years of dedication had been worthwhile, Zheng answered the question with another story.

Zheng said she was moved to tears once when her children gave her a surprise on her birthday: They bought a birthday cake using the money they had earned from collecting trash.

Zheng said that whenever she thinks of her children, she feels very proud and warm-hearted. At the No 12 house in the village, the wall of the sitting room is decorated with many family photos.

"Every day I stop to have a look at these photos. They remind me of the happy moments I spent with my children," Zheng said.

The SOS mother's devotion has touched the hearts of people in and outside the community. She has received many honorary titles over the years, including the "Model Worker in Shandong Province", "Ten Best Parents in Yantai", "Model of Morality in Yantai" and "National Advanced Worker" awards.

Pan Jie, Zheng's fourth son who comes back home to visit her every week, said he felt proud to hear the news that his mother was elected to be a delegate to the 19th National Congress of the CPC. Pan stressed that it was a reflection of her mother's selfless devotion.

Despite all the honors and acclaim, Zheng said she was only an ordinary mother who looked after her children as other mothers do every day.