Is it permissible for a marriage to be conducted with the consent of both parties and two just witnesses, but without the guardian (wali) of the girl, in order to legitimize the marriage after the occurrence of zina (fornication/adultery)?

The residence of youth in non-Islamic countries without religious deterrence is fraught with dangers, and may lead to the abomination of fornication (zina). Zina is a grave sin, and committing it necessitates sincere repentance and abandonment of the act. If a man commits zina with a woman, he is not permitted to marry her until after she has cleansed herself (istibra’) and repented. Furthermore, marriage without a guardian (wali) is invalid. The fornicator must offer sincere repentance by abandoning the sin, regretting it, resolving not to return to it, and staying away from the causes of disobedience. If he and the girl repent sincerely, then he may marry her with her guardian’s permission, and he must observe patience and chastity until marriage becomes possible.