Martínez represented Paraguay at two South American Under-17 Women's Football Championship editions (2013 and 2016), two FIFA U-17 Women's World Cup editions (2014 and 2016), three South American U-20 Women's Championship editions (2014 , 2015 and 2018) and two FIFA U-20 Women's World Cup editions (2014 and 2018). She has scored five goals in the Copa América Femenina (three in the 2014 edition and two in the 2018 edition).