What is the ruling on children attending mixed secondary schools if there is no alternative, given that they were raised with religious education and have memorized the Book of Allah, and what are the implications of neglecting their education, including the possibility of them resenting their father?

It is not permissible for one who has reached the age of religious accountability to study in co-educational schools due to the harm and corruption this entails for their religion. Therefore, it is obligatory to seek out non-co-educational schools. However, if this is not possible and no other option is available, then there is no harm in studying in co-educational schools, provided that extreme caution, vigilance, and close monitoring are maintained, and that one is urged to fear Allah and avoid direct intermingling. This is based on the jurisprudential rule which states: "That which is forbidden as a means (to a forbidden end) is permissible when there is a need."