It is narrated from Hazrat Mujahid (may Allah have mercy on him), if a Christian woman becomes Muslim and her husband remains Christian, he said: "If she becomes Muslim during the waiting period ('iddah), then her husband has more right to his wife."
Hadith Referenceسنن سعید بن منصور / كتاب الطلاق / 3160
Hadith Takhrij«أخرجه سعيد بن منصور فى «سننه» ترقيم الدرالسلفية برقم:، 1983، وابن أبى شيبة فى «مصنفه» برقم: 18628»