I think her hatred of Aes Sedai clouded her judgment in the White Tower. With her love of training and education, she could have slipped quite easily into the Seanchan to better effect.

She met my expectations for being pretty disappointing, honestly. For me the coolest parts of that extended battle scene was when Siuan first appeared to tell Egwene the battle had started and Egwene told the Wise Ones that "a Shadow Souled is here. I will fight." & they all agreed, Perrin bumping into Egwene in T'A'R (and her surprise that he was so good at manipulating the dream overshadowing any shock that he was there - she's so used to these things happening at this point that its' like "Meh. T'a'veren." and when Mesaana was defeated and Egwene was so focused on imposing her will that Eg didn't notice it at first.

She and Semirhage both had similar scenes with Egwene and Rand, though, and that was interesting to note on one level, but on another, I'm pretty sure Demandred will disappoint. His allies just didn't do to well, and to be honest, we've been greater opponents than him fall already, so this doesn't bode well.