That's why I used Elayne for my example. There's a clue in that which can be used to interpret something else I said.
Here are Elayne's distinguishing features as a channeler who comes to the Tower:
1) She's immensely strong in potential.
2) She's a noble of great power.
3) She's pregnant.
4) She was forced a little, but nowhere close to the extent Egwene was.
Elayne doesn't matter, it's about what Terez said about her. . It can lead you to make a simple logical deduction. That deduction, in the light of information from the series about Aes Sedai could lead you to one of the reasons why a potential may never be reached.
It's not very straight forward as far as clues go (even Terez wondered where I was going with that until I explained it). Once you make the right observation, you need to make a few more deductions. It's logical ones, though.