Does a wife whose husband has passed away retain guardianship over her adult children, or should their share of the inheritance be distributed, given that she and the two children are the sole heirs?

The default is that there is no guardianship over adult, mature heirs, and the estate must be divided, unless the heirs agree to postpone the division. Whenever one of them demands his right, it must be given to him. However, if they reach adulthood while not mature (extravagant with money), the money should not be given to them, and the interdiction over them continues, with the possibility of dividing the estate to distinguish each one's share.