Umm Kulthum bint Muhammad (Arabic: أم كلثوم بنت محمد) was the one of the daughters of Muhammad and his first wife Khadijah bint Khuwaylid according to Sunni Muslims. Muhammad gave two of his daughters to Uthman ibn Affan, the 3rd rightly guided Caliph of Islam. It is reported in a hadith that if the prophet had more daughters he would have also married them to Uthman.
It is reported in a hadith that he had said his daughter Fatimah would have the highest seat of all women in heaven, after the Virgin Mary. Fatimah was married to Ali, Muhammad's cousin and the 4th rightly guided Caliph of Islam. Her first husband was Utaybah bin Abu Lahab and her second was Uthman ibn Affan. Her other sisters were Ruqayah bint Muhammad, Zainab bint Muhammad and Fatima bint Muhammad. She died either in 9 AH (630 AD) or around the time of the battle of Badr (624 AD).
The truth is there isn't much to write. Sunnis claim that the Prophet (sawaw) had 4 daughters, but when asked, they can only provide info on one, Fatima (as).