I think that a part of the reason why we, as the reader, do not know much of the mother is because Ali's rebellion is not as staunchly aimed at her. Ali's rebellion is geared towards his father. It is Parvez who has embraced the West and all of the cosmopolitan trappings. He is the one who drinks, eats pork, seeks to boast about his son's exploits at cricket, and lives, for all practical purposes, a Westernized consciousness. It is at this that Ali seeks find difference. Perhaps, a reason why the reader is not entirely certain of the mother's role is that she is not the animus for his rebellion, Ali's distance. Ali seems to distinguish himself from his father, to the point where he is able to identify specific parts of the Koran that are being disgraced by his father. Additionally, Ali's embrace of the religion is antithetical to his father's, who has little regard of his own spiritual background. For all we know, the mother might be quite devout in her beliefs and might not arouse the level of Ali's disrespect as Parvez does. It seems that the rebellion and the need to distance himself is something that comes from the father's ways and not the mother. This might be the reason why we, as the reader, are not entirely sure of the function she serves in the narrative.