Is it permissible for the father to have custody of his son after divorcing his negligent Canadian wife who neither cares for her son nor raises him Islamically?

When a married couple separates, the custody of young children belongs to their mother, unless there is an impediment such as disbelief (kufr), immorality (fisq), or insanity. Scholars have differed on the age at which custody ends. Some are of the view that a girl, after reaching the age of seven, should be with her father, while a boy is given a choice. Others believe that everyone is given a choice after the age of seven. If you separate from your wife and she is Muslim and has no impediments, then the child is in her custody. If the mother's custody rights are forfeited, custody transfers to you, and it does not transfer to the maternal grandmother as long as she is a disbeliever. In case of dispute, the matter should be referred to the Sharia court or Islamic centers.