That's the first time we see it spovertly. But there is nothing to say it wasn't there before - Edit 1
Before modification by darius_sedai at 15/01/2011 09:56:21 PM
Think about the journey to Caemlyn. Bayle Domon appearing, Milie Skane just missing him with her knife... Who knows when it really started, but it's been stated that ta'veren seem lucky, or perhaps bend chance, and all 3 boys have been ta'veren since the very beginning of the series.