How can adult children be convinced of their mother's marriage to a religious man who fears God, while avoiding their objection or the occurrence of future problems with the new husband?

Marriage contains much good, achieving chastity and increasing progeny. The Lawgiver (Allah) has generally encouraged it, and there is no difference in this encouragement between a virgin and a previously married woman. A woman whose husband has died does not diminish in status if she marries after the completion of her waiting period (iddah). The Prophet, peace be upon him, said: "Marry, for I shall outnumber the nations by you, and do not be like the monasticism of the Christians." Moreover, the noble verse: "And those of you who die and leave wives behind them, they (the wives) shall wait (as regards their marriage) for four months and ten days. Then when they have fulfilled their term, there is no sin on you for what they do with themselves in a lawful manner. And Allah is Well-Acquainted with what you do," indicates the permissibility for a widow to adorn herself and offer herself for marriage after her iddah has expired. Indeed, the wives of the Companions married after the deaths of their husbands. It is incumbent upon the children to help their mother marry a righteous husband. If the mother fears objection from her children, she should seek assistance from a relative and seek guidance from Allah (istikharah).