Did Khadijah have children from a previous marriage before the Prophet, peace and blessings be upon him, and is it true that Fatimah is not the daughter of the Prophet, but rather Khadijah's daughter from a previous husband?

The Mother of the Believers, Khadijah bint Khuwaylid, may Allah be pleased with her, married two men before the Prophet, peace and blessings be upon him: the first was Atiq ibn A'idh, and the second was Abu Hala al-Tamimi. She bore children from both of them, and there is a difference of opinion regarding the order of her marriages to them.

Muslims do not differ on the fact that Fatimah, may Allah be pleased with her, is the daughter of the Messenger of Allah, peace and blessings be upon him, from his own loins and from his wife Khadijah, may Allah be pleased with her. This is established by numerous noble prophetic narrations.