>>>>A woman carries cells from her children, and children carry their mother’s cells. I don’t see how a woman could carry her sex partners’ cells.
It can’t happen from just having sex... but it can happen from a pregnancy, especially where the child is male. I’m not a doctor so I’ll now duck out of this discussion but I had heard this before and quickly found a couple of links. The process is called microchimerism and it basically is the result of mothers and babies exchanging blood through the placenta...
https://www.livescience.com/62930-why-mom-keeps-baby-cells.html
https://www.insider.com/why-women-retain-male-dna-2018-3
The articles you kindly linked to say that women pick up chimeric male cells from their sons during pregnancy, and possibly from brothers’ cells in their own mother’s womb, not from sex partners.