I'm from Canada and we received group of reciters from Indonesia. Among them was a woman. My question is : Is it allowed for a woman to make a public recitation or to be a reciter?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Legality of women's recitation of al-Qur'an in the presence of men is governed by Shari'a ruling concerning her voice. Thus, we have two states.
1- A woman's voice is normal, i.e. without stretching, humming and so on.
2- A women's voice is with tone, stretching and so on.
There is no harm for a man to speak with her, listen to her and discuss with her unless one may be pleased by talking and listening, i.e. it becomes Haram as in Ahmad's narration even while reciting the Qur'an.
As for the second state, it is Haram for a woman to speak in the presence of alien men as long as there is stretching and so on in her voice and it is Haram for men to listen to her. Since it is normal for a reciter of al-Qur'an to demonstrate intonation, it becomes disliked for a woman to raise her voice while reciting, fearing temptation. But, if temptation is not possible, then she can recite and others can listen.
According to al-Shafi'ay, it is disliked for a woman to perform her prayer loudly in the presence of alien men for fear of temptation.
In 'Kashf al-Qinaa, a woman is required to perform her prayers secretly in the presence of alien men.
According to Ahmad from 'Mahna' that a woman is advised to pray secretly at night.
Then too, if such a woman traveled to Canada without a Mahram, she would commit what is Haram, and she is required to repent.
Allah knows best.