Sayidah Um-Kulthum bint Ali is also referred as Zaynab as-Sughra, after her older sister Sayidah Zaynab al-Kubra bint Ali. Sayidah Zaynab al-Kubra and Sayidah Zaynab as-Sughra, both the daughters of Imam Ali and Sayidah Fatimah , side by side faced the harships and oppression (from the Banu Umayyah (ln)), yet bravery in Karbala and Sham with the other ladies of the Banu Hashim, the family of Rasuwlallah .
Um-Kulthum bint Ali is one of the two daughters of Imam Ali and Sayidah Fatimah Zahra . Um-Kulthum bint Haalah was a daughter of Hadrah Khadijah's sister called Haalah whom upon death Hadrah Khadijah took guardianship of then the Holy Prophet adopted upon marriage with Hadrah Khadijah . All Haalah's 3 daughters called Um-Kulthum bint Haalah, Ruqayah bint Haalah & Zaynab bint Haalah were adopted by Rasuwlallah . Neither Rasuwlallah nor Hadrah Khadijah had any children bore to them before their blessed marriage. The holy Prophet and Hadrah Khadijah had only one daughter named Sayidah Fatimah az-Zahra (sa) and 2 sons named Qasim and Tahir, both sons desceased in early infancy.
Um-Kulthum bint Haalah, the adopted daughter of Rasulallah and Hadrah Khadijah was married to Omar or Othman. Whereas Sayidah Um-Kulthum bint Ali was married to Muhamad ibn Jafar at-Tayaar ibn Abu-Taalib .
Sayidah Um-Kulthum bint Ali had no children of her own, however Hadrah Abbas ibn Ali , her half-brother was like her adopted son.
'Um-Kulthum' is an old Arabic name that is joined (two words that mean one thing / ism murakkab) so it does not mean she is the mother of Kulthum but that is basically how her name is to mean something or posses something.
Rasuwlallah did refuse the hand of Omar and Othman for his only true daughter Sayidah Fatimah Zahra but waited and accepted the hand of Imam Ali ibn Abu-Taalib(as) .
The birthday / Eid Milaad of Sayidah Um-Kulthum bint Ali AKA Zaynab as-Sughra is on the 18th Rabiy al-Awwal, a day after the Milaad an-Nabi . Her sacred shrine is in Sham (now called Dimishq) in Baab as-Saghir along with many Shuhada .