Magno was born in Baguia, in the then Portuguese Timor, to Ana Xavier G. Magno and Alberto dos Reis Magno. Eleven months after her birth, Indonesia began its occupation of East Timor. Magno's family fled to Mount Matebian, a centre of the Fretilin resistance against the occupiers. The family lived on the run for four years before returning to Baguia in 1979. In 1980, the family surrendered to the Indonesian army because its members were in danger of starvation.