Must a sum of money inherited by the grandmother from her father, and which she relinquished to her children before her death but was not given to her, be donated as charity?

If the grandmother relinquished the amount to her children while she was of sound mind and fully competent to dispose of her property, and the children took possession of the amount, then the relinquishment is valid, and the children own the money and may dispose of it as they wish. However, if she relinquished it during her death illness (marad al-mawt), her relinquishment is considered a will, and it is not valid for more than one-third of the estate unless the heirs agree. Whatever exceeds one-third belongs to the heirs.