Dr. `Abdul-Fattah `Ashoor, Professor of the Exegesis of the Qur’an at Al-Azhar Univ., states: “When a Christian woman is married to a Muslim man, she should follow the Islamic rule regarding `Iddah (waiting period) as Allah, Exalted be He, has explained. Thus, if she is divorced or becomes a widow, she must wait until the prescribed (`Iddah) period pointed out in the Qur’an and Sunnah of the Prophet (peace and blessings be upon him) expires.
Therefore, it is the duty of any Muslim who is willing to marry this Christian woman after her being divorced or widowed to be assured that her waiting period has expired before getting married to her.”