Some quotes regarding the Kin.

**TITLE: A Crown of Swoards, CHAPTER: 30 - The First Cup

"The Kin persisted even after Barashta fell, in the same way they had before, taking in wilders and women put out of the Tower."

"None ever remained long," Adeleas added. "Five years, perhaps ten; then, I suppose as now. Once they realize that their little group is no replacement fot the White Tower, they go off and become village healers or Wisdoms or the like, or sometimes simply forget the Power, stop channeling and take up a craft or trade. In any case, they vanish, so to speak."

"The Tower has known of the Kin from the nearly the beginning, perhaps from the very begining. At first, no doubt, the [Trolloc] Wars took precendence. And despite calling themselves the Kin, they have done just what we want such women to do. They remain hidden, even the fact that they can channel, draw no attention whatsoever to themselves. Over the years, they have even passed along word -- secretly, of course; carefully-- when one of them found a woman falsely claiming the shawl."

Elayne [asked] "Why is knowledge of them such a deep secret? Why haven't they been scattered long ago?"

"Why, the runaways, of course" Adeleas made it sound the most obvious thing in the world. "It is a fact that other gathering have been broken up as soon as found -- the last about two hundred years ago -- but the Kin do keep themselves small, and quiet. That last group called themselve the Daughters of Silence, yet they were hardly silent. [...]"

It goes on, basically it reveals that prior to the Kin, 67-75% of WT runaways got away clean, and since the Kin were formed the rate of runaways not caught has always been less than 10%. And the Kin are tolerated because they act the way the WT wants them too.

Which leads to my theory. My theory is that the WT always knew about the Kin as a group, and tolerated them because they acted in a way that the WT approved of. The WT thought that they took in wilders because when a Kinswoman faked her death after enough years, the WT actually believed it (they watched each Kinswoman for a few years, enough to realize that they acted "within bounds" and then not being concerned, stopped watching or didn't watch so hard, so a faked death could slip past them). So the returning older Kin were thought to be wilders because the WT didn't realize that the Kin lived so long, and the WT thought that the Kin left or died when actually they didn't because the level of watching the Kin wasn't strong/detailed enough to overcome the extremely circumspect and low profile that the Kin have kept. If the Kin hadn't acted on such good behavior, then the watching would have been stronger and they would have been acted against, like other groups of female channelers were watched and acted against.