Well whatever you two decide to do, as I was trying to tell Keys earlier, it takes time for word to reach anywhere, even with the aid of magic.  My idea was that during such a delay, No'Lien was in Whitestone for a while, either because she hadn't left yet or because she had gone back for a while, (although I'd prefer she not have been in Emon long enough to DO anything against the Clasp just yet), and Keri shows up in town.  They meet up, she gets word from Vex in Emon, and they go back to the city together.  That was just my idea though, but whatever you decide to do, I DON'T want you guys dismantling my whole plot before the game even starts lol.  That's why I'm kinda bleh about you having been in Emon long at all.  That and I'm more of the mind Vex called on help from her niece without consulting ANYONE in the city so no one had a chance to prepare for her arrival.