What is the ruling on a Muslim man marrying a non-Muslim woman who has been separated from her non-Muslim husband for two years, knowing that her civil divorce has not yet been issued? And what is the ruling if she converts to Islam?

It is not permissible for a Muslim to marry a polytheist woman, but he may marry a chaste woman from the People of the Book. If a woman from the People of the Book is divorced and her waiting period (iddah) has ended, it is permissible for a Muslim to marry her. However, if her husband has not divorced her, it is not permissible to marry her, because the marriages and divorces of disbelievers are valid. If a woman embraces Islam and her waiting period ends, and her husband does not embrace Islam, her marriage is annulled, and it becomes permissible for her to marry a Muslim. It is advisable not to marry before obtaining a divorce certificate from the first husband to avoid complications.