Plus, it is convenient that Aran'gar, who Graendal has recently cemented a partnership is nowhere in the book, either.

It would be convenient for Aran'gar to let her know a massive amount of saidin is being channeled in time for her to leave or for her to Travel to another safespot due to wards being triggered when a male channeler entered area.

Graendal doesn't get pumped up as easily as other Forsaken. As soon as Moridin told her to stop playing games, she dropped the pretenses, and I believe she was thinking of how to accomplish what she needed from a safe spot.

Heck, she could have Linked with another woman, had her weave the Compulsion, and then left when the messenger was sent away. There are a lot of possibilities here and the fact that the exterior of her palace just doesn't match up with prior recollections sends a warning bell to me that Rand was lead to the wrong place.