All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Fornication and/or adultery is one of the great major sins and Allaah has warned us against it saying (which means): {And come not near the unlawful sexual intercourse. Verily it is a Faahishah (i.e. anything that transgresses its limits; a great sin) and an evil way (that leads one to Hell) unless Allaah forgives him/her.}[Qur'an 17:32]. So this woman has to repent to Allaah and avoid any means that could lead her to commit the same sin again. She is also obliged to conceal her sin. It is confirmed that the Prophet said: "All my nation is pardoned except those who openly expose their sins." [Al-Bukhari and Muslim] On the contrary, it is not permissible to mention the name of the person with whom she committed fornication as, if she does so, she is accusing him without providing four witnesses, and this is one of the great major sins. She should avoid establishing any kind of relationship with a marriageable man, whether that is the man with whom she had already committed fornication or any other man. If her husband asks her to stay away from those men, then the matter is more confirmed in her regard. The Prophet said: "If I were to order someone to prostrate to other than Allaah, I would have ordered the wives to prostrate to their husbands for the great right Allaah made due to them from their wives." [Abu Daawood] So, if this woman stops doing or saying the above-mentioned things, then all perfect praise be to Allaah, otherwise she is a disobedient wife. In such a case, her husband should follow the steps that Allaah has stated in dealing with a disobedient wife and these are mentioned in Fatwa: 89480.
Allaah knows best.