It is narrated from Yazid bin Asam that Lady Maymunah (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings be upon him) married me at the place of Sarif on his return from Makkah, at a time when we had become lawful (i.e., were out of the state of Ihram).
Hadith Referenceسنن دارمي / من كتاب المناسك / 1862
In this narration, Umm al-Mu’minin Sayyidah Maymunah bint al-Harith radi Allahu anha herself refutes the claim that the Messenger of Allah sallallahu alayhi wa sallam married her while in the state of ihram. The narrator, Yazid bin Asam, is the nephew of Sayyidah Maymunah radi Allahu anha, as is mentioned in the narration of Sahih Muslim, that Sayyidah Maymunah radi Allahu anha was the maternal aunt of both myself and Sayyiduna Ibn Abbas radi Allahu anhuma.