I have thoughts ...

1. Brandon has confirmed that it is Verin's weave that is being alluded to here. I think Verin compelled those Sisters to support Rand, which was once again her underminding the BA. It also explains Elza's massive epiphany that she must help Rand reach the Last Battle.

2. She was told to tell Semirhage that she had Compulsion on her. This is most unusual. Firstly, it means that someone of immense skill delved her (Verin said she was the most Talented delver in the White Tower). Secondly, that person could not do it themselves. These two facts point to Shadar Haran, but he can only sense saidin or saidar, he can't tell what it is, and it's remarkable that he could sense such a minute amount in Elza hidden so deeply. It's also odd that he told Semirhage about it. My only thought here would be that it would help Semirhage explain any odd or unacceptable behaviour in Elza, which would prevent her from killing her for insubordination immediately. Yet, did Semirhage unravel this weave? She said it was very dangerous but she can do it. And yet, Elza later seems horrified at the situation she finds herself in - she even pleads to Semirhage. Either this is still the Compulsion in effect that Semirhage decided to leave, or Elza is shocked at Semirhage's cruelty and she can't handle it.

Thoughts?