The waiting period of the wife who has embraced Islam and got divorced through a judicial decree while her husband remains a non-Muslim is counted from the time of the decree, not from the time of her embracing Islam.
Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states the following: The wife who has embraced Islam while her husband has not and, consequently, has got a divorce decree from the court should calculate her `iddah from the time of the decree, not from the time of her embracing Islam. That is because the husband’s abstention from embracing Islam is considered as a kind of separation between him and his wife, which depends upon the judiciary. This is the opinion of Imam Abu Hanifah, on which the personal law in Egypt is based. (See Sheikh `Abdur-Rahman Taj’s Al-Ahwal Ash-Shakhsiyyah, p. 241.)