Anyway, I think you may be looking for the most obvious candidate. Elaida, for example, was not a DF despite her hatred of Rand and Rands' friends. Who turned out to be Darkfriends? Verin, Sheriam and Ingtar - characters who have helped Rand & Co. and have been somewhat close to their missions.

It seems to me that the Darkfriends are turning out to be the most non-obvious candidates, hence someone like Sorilea who simply wants to see her people survive might work through the other Wise Ones so her part in the scheming would not be obvious, the same way Mesaana and Alviarin were setting up other Aes Sedai to do the dirty work.