All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
This act is not among the real Zina (fornication or adultery) that requires the Hadd (i.e. the corporal punishment determined by the Islamic Law), but it is one of its means, and it is also forbidden. Allah has warned us against it as He Says (what means): {And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way.} [Quran 17:32]
Ibn Katheer said in his Tafseer: “Allah the Exalted says while forbidding His Servants from Zina, from approaching it, and engaging in its causes and motives: {And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality…}” [End of quote]
This girl was wrong by her taking a boyfriend and enabling him to be alone with her, and by that, she was the cause that led her boyfriend to force her to do that. Nonetheless, the son of Adam is not free of errors (sins), but the best of the sinners are those who repent as it is proven in the authentic Sunnah.
Our advice to this husband is that he should not look at his wife’s past; rather, he should consider her present situation. So, if she is righteous now, then he should keep her as a wife and keep good marital relations with her and maintain his family in a strong bond, especially that they are blessed with children.
Forgetting the past about his wife is easy and possible if the husband has a sincere determination, strives about this matter, and supplicates Allah to facilitate that for him. He should also observe the Ath-kaar (mention of Allah) and seek refuge in Allah from the accursed Satan to avoid indulging himself in any bad thoughts.
It is obligatory to conceal the sin of this woman and not inform anyone else about what she did as it is not permissible according to the Sharee’ah to expose someone who does not openly commit sins and just erred and sinned once, as mentioned by the scholars. Abu Hurayrah narrated that the Prophet said: “Whoever conceals the sin of a Muslim, Allah will conceal his sin in this worldly life and in the Hereafter.” [Muslim]
Allah knows best.