((Shias say that Prophet Muhammad (SAW) had only one daughter (Fatima R) while Sunnis believe that he had four daughters, Fatima, Ruqayya, Zainab, and Umm Kulthum (R). Which view is correct?
According to the Quraan, Prophet Muhammad (SAW) had more than two daughters. Allah says in the Quraan:
O Prophet, tell your wives and your daughters (banaatika) and the women of the believers that they should cast their outer garments over their persons (when abroad): That is most convenient, that they should be known (as such) and not molested. And Allah is Oft-Forgiving, Most Merciful. Chapter 33 (Al-Ahzab) Verse 59
In this verse, the word for daughters is banaat which means more than two daughters. (bint is singular, bintaan/bintain means two daughters and banaat means more than two.) Since Allah used the word banaat, it means that the Prophet had more than two daughters, so Sunnis are correct in this case.
This also means that Prophet Muhammad (SAW) had sons-in-law in addition to Ali (R), so any reverence that Shias give to Ali (R) on the basis that he is Prophet Muhammad (SAW)'s son-in-law has to be given to the other sons-in-law as well, such as Uthman (R). If they revere Ali (R) over the other Ashaab because he was the Prophet's son-in-law, then they have to revere Uthmaan (R) as well because he also was the Prophet's son-in-law.)))

Amongst the Shia there is a difference of opinion in the number of daughters the prophet (s) had. Some believe Fatima (as) is the only daughter, some scholars believe the prophet had other daughters with Khadija, and some scholars believe thosewere his foster children who were khadija’s sisters children