Must the estate of the deceased husband be divided after 38 years of his death so that his wife's conscience is clear before Allah, knowing that some of this estate has been disposed of during that period?

What the deceased leaves behind, whether buildings or agricultural lands, is considered an inheritance. If a monthly pension was saved for him from his salary after his death, it is added to his inheritance and distributed among his heirs. However, if the pension is a grant from his employer and not something the deceased was entitled to, then its disposition is as the granting entity sees fit. Your past management of the inheritance, if it was by virtue of guardianship over minors, is considered valid if it was in their best interest. However, after they reach maturity, you have no right to manage it except with a power of attorney from them, and none of them has the right to independently dispose of any part of the inheritance except with everyone's permission. This matter should be presented to the Sharia (definition) court or knowledgeable scholars to justly divide the rights.