Zaynab (may Allah be pleased with her) was the first to join the Prophet (peace and blessings be upon him) after his death

It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) said to his wives: "The first of you to join me will be the one with the longest hand." Sayyidah Aishah (may Allah be pleased with her) says: After the death of the Messenger of Allah (peace and blessings be upon him), whenever we gathered in the house of one of us, we would place our hands against the wall and compare their length with one another. We kept doing this until Sayyidah Zaynab bint Jahsh (may Allah be pleased with her) passed away. She was a short woman and was not the tallest of us. Then we understood that by the length of the hand the Prophet (peace and blessings be upon him) had meant charity. Sayyidah Aishah says: "Sayyidah Zaynab (may Allah be pleased with her) was skilled with her hands; she would tan leather and sew, and give it away in charity in the path of Allah."
This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Amir that Sayyidah Zaynab bint Jahsh (may Allah be pleased with her) used to say to the Prophet (peace and blessings be upon him): "I have a greater right over you than all your wives: my marriage was the best of them, my envoy was the most honoured, and I am the closest to you in kinship." Then she would say: "The Most Merciful, the Mighty and Majestic, married me to you from above His Throne, and Jibril (peace be upon him) was its envoy; and I am the daughter of your paternal aunt, and none of your wives besides me is so closely related to you." (As I have mentioned, her mother Umaymah bint Abd al-Muttalib was the paternal aunt of the Prophet (peace and blessings be upon him).)