Ngui competed in the 2004 Summer Paralympics in Athens, Greece. There she went out in the semi-finals of the women's 100 metres — T12 event She also competed at the 2008 Summer Paralympics in Beijing, China. There she won a bronze medal in the women's 100 metres — T12 event and a bronze medal in the women's 200 metres — T12 event. Her 200-meter bronze medal came after the Spanish delegation complained that the Angolan runner Evalina Alexandre who finished ahead of her had been assisted by her guide in a way that violated the rules. Upon review, race officials agreed and then award Ngui bronze.
