Is the marriage proposal of the Prophet, sallallaahu 'alayhi wa sallam, to Faakhitah bint Abi Talib true? Detailed information is found here: https://en.wikipedia.org/wiki/Fakhitah_bint_Abi_Talib

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

The story of the Prophet proposing for marriage to his cousin Faakhita, Umm Haani, was reported in detail by Al-Haakim in Al-Mustadrak from Muhammad ibn ‘Umar, who said:

“It was mentioned that the Messenger of Allah proposed to his uncle, Abu Taalib, to marry Umm Haani before any revelation came down to him. At the same time, Hubayrah ibn Abi Wahb proposed to her, and Abu Taalib married her to Hubayrah. So the Prophet said to him, ‘O Uncle, you married her off to Hubayrah and left me out?’ Abu Taalib replied, ‘O my nephew, they are our in-laws, and the dignified rewards the dignified.’ Then she embraced Islam, and Islam separated between her and Hubayrah. After that, the Prophet proposed to her (directly), and she said, ‘I swear by Allah, I loved you before Islam, let alone now that I am a Muslim, but I am a woman with children, and I hate that they would harm you…’”

We have not come across any scholar who ruled this narration as Saheeh (sound) or Dha'eef (weak), and Ath-Thahabi omitted it in his book Talkhees Al-Mustadrak.

There is another short narration reported by At-Tirmithi, and it is also present in Al-Mustadrak, it says that Umm Haani bint Abi Taalib, may Allah be pleased with her, said, “The Messenger of Allah proposed to me, and I apologized to him and he pardoned me.”

At-Tirmithi said, “This hadeeth is Hasan Saheeh (good or sound).” Al-Haakim classified it as Saheeh in Al-Mustadrak, and Ath-Thahabi agreed with him, but Shaykh Al-Albaani classified this narration as Dha’eef (weak) in his book Dha’eef Sunan At-Tirmithi.

Therefore, there is a difference of opinion on whether this narration is authentic or inauthentic.

Allah knows best.