Is it advisable to delay the inheritance of a disobedient child by a mother after his father passes away?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

There is no doubt that undutifulness towards parents is one of the grave sins; however, if the son is an adult, then his undutifulness is not a valid reason to justify denying him his share of the inheritance, limiting his legal competence, or delaying to give him his share.

However, if the son has not yet reached puberty, as understood from using the word "child" in the question, then this means that he is legally incompetent (to make use of his property) because of his young age, regardless of whether he is dutiful or not. In this case, he is not entitled to dispose of his share in the inheritance; instead, his share should be identified and given to his legal guardian or wasiyy (authorized agent or caretaker) after his father’s death. The wasiyy is the person whom the father authorized, before his death, to take care of his affairs. If the father did not appoint anyone, then the child’s grandfather (the father’s father) is the legal guardian of the young child. If the child has no grandfather, then the Muslim judge in the sharee'ah court should appoint a wasiyy. If there is no sharee'ah court, then a trustworthy person should be chosen to act as his wasiyy; there is no harm if the mother assumes guardianship over her child in this case.

Kashshaaf Al-Qinaa‘ reads: "If the father did not appoint a wasiyy who possesses the required qualities (for guardianship) before his death, or the father (existed but) lacked the required qualities as indicated (by the author) in the book Al-Hibah (gift), then the Muslim judge should appoint a trustworthy caretaker to take care of the orphan and the insane person, as the legal guardianship is to be transferred to him. If there is no Muslim judge or he is lacking the required qualities, then a trustworthy Muslim person should be appointed as a caretaker of the orphan. Al-Athram was asked about a man who passed away and had young children, what should be done with their shares of the inheritance? He replied, 'If the young children have no wasiyy and have a compassionate mother, then their shares should be given to her (as their legal guardian).'"

Allaah Knows best.