Is it permissible to withhold inheritance from an elderly, ill mother whose son passed away without informing her of his death, while preserving her right to the inheritance? And is it possible to waive her share to the deceased's children without her knowledge?

Ownership of inherited wealth transfers to the heir at the time of the deceased's death, and rights such as Zakat (definition) and debt repayment become attached to it. The mother's share of the deceased's estate is one-sixth if he had a child, and one-third if he had no child and his parents inherited from him, and one-sixth if he had siblings, after any bequest he made or debt. There is no harm in delaying informing the mother of her son's death if there is a fear of harm. It is not permissible to dispose of her wealth by giving it to her brother's sons; rather, her share must be preserved, and her guardian of wealth may only spend from it for her benefit, and her permission and consent are necessary if she is not legally incompetent.