What about khul' (a wife's right to divorce her husband) in early Islam?

The first khul' in Islam was the khul' of Jamila bint Abdullah ibn Ubayy, the wife of Thabit ibn Qays, when she came to the Prophet, peace and blessings be upon him, and said that she detested disbelief in Islam because of him. So he separated them in exchange for his garden. Some scholars have gone to the extent of saying that khul' occurred in pre-Islamic times (Jahiliyyah), and the first khul' among the Arabs was when 'Amir ibn Al-Dharib separated his daughter from her husband, 'Amir ibn Al-Harith.