Her family went into exile in Australia when Pires was nine years old, during the Indonesian occupation of East Timor.
She studied sociology and English literature, receiving a Bachelor of Arts from the University of New England.
She received funding from the Catholic Institute for International Relations to research domestic violence in East Timor.
On 12 April 2016, Pires was appointed by President Taur Matan Ruak as East Timor's Permanent Representative to the United Nations.
[1] Pires is married to former Foreign Minister and CPLP Executive Secretary Zacarias da Costa and they have one son.