When people in The Western countries talk of Muhammad's wife they most often think of Aisha, the 6 years old girl, he married, "consummating their marriage" when she was nine. However, he had 13 wives, and No. 7 is kind of special. Her name was Zaynab bint Jahsh and she was not only his cousin, but also his daughter-in-law as well as his wife.
HOW is that even possible??? Well, Zaynab was the daughter of the sister of Muhammad's father and thus his first cousin. She was born in 590 and died in 640/641 as one of the widows of Muhammad who had died in 632, her third husband. Little is known about the first one who seems to have died in 622, but No. 2, Zayd Ibn Harithah, started out as the slave that had been a gift from Muhammad's first wife, Khadijah. Muhammad never had a biological son which may be the reason why he adopted this slave and made him his son. Maybe he married him off to his cousin, Zaynab, to boost his status in society, but the legend is that all of a sudden Muhammad was beset by the beauty and sex appeal of his cousin + daughter-in-law, Zaynab, and poor Zayd ended up in a very, very hot spot which he tried to get out of by divorcing his wife. Not that it saved his life because it didn't: He was sent off on a military mission that (was meant to???) end with his death.
What also died was the Muslim adoption system as all of a sudden it was not seen as acceptable.
As to Zaynab she was a skilled tanner by profession and went on in her trade, both before and after the death of Muhammad. However, she also seems to have been a great humanitarian as she was reputed to have given away all her profits to the poor of Medina and always having a heart for those in need.
https://neareasternstudies.cornell.edu/node/9478
Wikipedia