Nafi' (may Allah have mercy on him) said that Rubayyi' bint Mu'awwidh (may Allah be pleased with her) and her paternal uncle came to Abdullah bin Umar (may Allah be pleased with them both), and she told him that she had taken khul' from her husband in the time of Uthman (may Allah be pleased with him). When Uthman bin Affan (may Allah be pleased with him) learned of it, he did not object. Abdullah bin Umar (may Allah be pleased with them both) said: Her waiting period (iddah) is the waiting period of a divorced woman.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الخلع والطلاق / 14858