As her parents lived in an illegally erected home, she had no birth certificate and was denied admission to a public school.

She started working on the docks of the Bangkok port, packing firecrackers and scraping rust off ships' hulls.

When the slum dwellers were threatened with eviction by the Port Authority of Thailand (PAT) which wanted to expand its facilities in 1972, a Bangkok Post reporter interviewed Prateep and her cause was publicly known.

[3][4] She used the prize money to establish the Duang Prateep Foundation (DPF; "flame of hope") and became its secretary general.

[7] Her commitment to the "Red Shirts" and the political polarisation in Thailand led to a decline of donations for her Duang Prateep Foundation from within the country.

Some regular donors who are affiliated with the opposite political camp refused to give to an organisation headed by a "Red Shirt" and stopped their payments.

[8] In 1987 she married the Japanese citizen Tatsuya Hata, a Kinki University professor for international studies and charity activist.