Certainly there are a few with the latent ability, one of the Wisdom's even tells Faile that some Wisdom's can Listen to the Wind, but not all of them. I imagine only a Wilder would have that ability, but none of the current Wisdom's can LttW thus none can Channel actively.

In order to be a Wilder you must have the Spark and survive the source potentially killing you. Nynaeve is the only true Wilder from the TR we've seen... we did hear about her predecessor as Wisdom's apprentice dying of what was likely Channeling sickness though.

Nynaeve said she was specifically training Egwene to replace her someday. It's not really important, just a side note to my point. But either way Nynaeve would have at some point been noticed as not growing older. She would have eventually been marked off as odd for this in the TR and likely would have wound up leaving the region.

It's the case with any Wilder if you think about it... these women have no idea why they stay so young (having never gone to the Tower) and the villagers around them must find it unsettling to have a woman in her 80's look like she's in her 20's ... these women can live upwards of 500-600 years and likely be well over 200 before they start even appearing middle aged.