Is a mother sinful for depriving her daughter of parental affection and the joy of living with them, by leaving her in Morocco with her grandmother to learn Arabic, knowing that the child cries because of the separation from her parents?

It is a child's right upon his parents to be raised upon the religion, as Allah Almighty says: [O you who have believed, protect yourselves and your families from a Fire]. A child's upbringing in lands that do not value religion may lead to their ruin. Therefore, there is no harm in raising the daughter with her grandmother, as the grandmother has the right to custody after the mother. The daughter's crying is natural at first, and she will grow accustomed to her grandmother over time.