She is smarter than Rand is, as he himself admits. I'm sorry, but it really takes a lot of effort for me to believe that she won't run away after the Dragon Reborn shows up on her doorstep, sends a messenger to her *on foot* (basically screaming Gateway/Travelling weave) or sees a massive stream of balefire hit portions of her palace and remove them from the Pattern. Balefire removes sections from physical objects - not the entire thing. Thus balefiring a column will leave sections missing that will cause unsupported sections of masonry to fall or fracture. She could literally have been sitting on her throne when she saw a massive stream carve it's way through sections of her palace. This is analogous to the scene in TSR where Rand tries to channel though he is exhausted, and sends a massive stream of Balefire between Lanfear and Asmodean, which was so huge it should have destroyed both, but Lanfear just jumped back from it.

I'm still of the opinion that people forget the fundamental rule of dealing with Super Villains: Never be sure that someone is dead until you see the corpse and make sure it's the bad guy. Egwene learned this lesson, even though the person wasn't quite bad.

I think so many people get caught up in massive demonstrations of destructive weaves with the One Power that they forget it's not a normal magical force - it needs to be aimed, it's effects operate on a few laws that can be deduced from experience and I think the most obvious thing, is that effects that are tied can last forever, but effects that are maintained can be cut off at any time. As Birgitte herself said in the last book during the Battle at Caemlyn, soldiers got so freaked out by attacks of the One Power that they were often surprised that they survived them at the end of the battle.

Personally, I think that as soon as his messenger showed up, Graendal gulped down some wine, grabbed a few of her most prize trophies and herded them off to Headquarters #2, where she watched him balefire her subjects from a safe distance.