How did Umm Kulthum and her son Zayd die in the year 40 AH or 41 AH, yet she was present at Karbala in the year 61 AH? And how could Abdullah ibn Ja'far have married her if she died before her sister Zaynab? What is the date of death for Umm Kulthum and Zaynab and their cousins, Ja'far's sons? And did Umar ibn al-Khattab have progeny from Umm Kulthum?

Summary of the Answer:

It has not been established that Abdullah ibn Ja'far married Umm Kulthum after Zainab's death, but rather after Zainab's divorce.

Most history books mention that Umm Kulthum died before the Battle of Karbala, while Zainab witnessed it.

Abdullah ibn Ja'far married both Umm Kulthum and Zainab, and both of them died while married to him. Most sources mention that his marriage to Zainab was before his marriage to Umm Kulthum.

Abdullah ibn Ja'far first married Zainab and then divorced her. He then married her sister, Umm Kulthum. When Umm Kulthum died while married to him, he returned and married Zainab again, and she remained his wife until she died while married to him.

Abdullah ibn Ja'far had several sons and daughters from different wives. From Zainab bint Ali, he had four sons and one daughter.

Umar ibn al-Khattab had one son and one daughter from Umm Kulthum bint Ali: Zayd and Ruqayyah. Zayd died with his mother and had no offspring mentioned, while Ruqayyah married Ibrahim ibn Nu'aym and died while married to him without having children.

Zayd died around the year 50 AH, while Ruqayyah died before the year 63 AH.