[@Ezmeralda] I would normally agree with your first point, except that it doesn't make sense, given my point that you cannot put all your eggs into one basket. Additionally, during the Trolloc Wars, [b]plenty of Aes Sedai stayed behind in the White Tower to defend Tar Valon-[/b] there were four major assaults on Tar Valon, so they had to keep significant forces at their home base. Novices, Accepted, and the younger Aes Sedai were among those who stayed at the tower. 

I don't remember that quote, but the series is hella long, so I don't remember a lot of quotes, lol. And yes, Healers can be very weak, but the White Tower would train them to their full potential before letting them out into the world. And if your character becomes a novice at the youngest age that I've seen in reading the Companion (which is 16), then does her training in half the time other people do, that still gives her only 5 years so far that she could train in Healing. And I do not think that that could get anyone to their full potential- again, a 31 year old Aes Sedai is the equivalent of a 6 year old child.