Is the marriage of a 39-year-old widow to a 45-year-old man valid, given that it was conducted by the mosque's sheikh in the presence of two witnesses, with offer and acceptance, but without a dowry, knowing that he presented a gift two days later and that the marriage is secret with the intention of publicizing it later?

The guardian (wali) is one of the pillars of marriage. If one of the guardians is present, and another person contracts the marriage for the woman, then the marriage is invalid and must be renewed in the presence of the guardian who has the most right to give her in marriage. This is unless the person contracting the marriage is a Sharia (definition) judge who considers the marriage valid without a guardian. The children born before the renewal of the contract are attributed to the husband. If none of the guardians are present, then the marriage is valid and effective, and the lack of explicit mention of the dowry does not affect its validity. In this case, the wife is entitled to a dowry equivalent to that given to women of her status (mahr al-mithl). A marriage contracted in the presence of two witnesses is not considered a secret marriage, and announcing and publicizing the marriage is only recommended.