In 1986, when she was 19, Bustamante began working as a domestic helper in Singapore. During her three years in the job, she also studied Accounting at the Open University of Singapore Institute of Management. She was even able to finish the undergraduate program without her employers knowing it. “I did my studying during the evenings when everyone was asleep. From 11 in the evening to 1 a.m. [I would] start my job at 5 a.m. I was only given a day off. That one day off I would go to school to talk to my professors and get my whole month's worth of homework,” she said.