This may be a long shot, but I think that Verin may be Corianne Sedai. First she is the only one who knows that the notes about the dream ter'angreal exist. Second it is said somewhere in the series, that a long time ago the oaths weren't required to become Aes Sedai. This would explain the way that she lies occasionally, She mentions being involved in the plot with the dragon for seventy years. Every Aes Sedai seems to follow her whenever she decides to lead.( When power is in doubt, the time they've been Aes Sedai is used for leadership purposes.) Now My theory is sometime probably during trolloc wars She vanished for a time, and was assumed to be dead. She came to the tower at a much later time and to conceal who she is for future plans claims another name. The reason this is accepted is because she is experienced in the power is very strong, and surely in time of war, some records will be lost I know this sounds a little thin, but it's just something that occured to me.