She is surprised at how clever he has become. She says straight out that he has become far more dangerous than she had assumed. She is angry that all her pets and OP objects, her safest lair and her closest ally among the Chosen have been destroyed.

She then thinks, though, that she feels the safest she has ever felt since she was released from the Bore, since Rand now thinks she's dead. Except the DO wouldn't be pleased she'd caused the death of one of the Foresaken.

It is interesting to me that she feels safest now. It shows clearly that unlike the men like Rahvin, who dismissed Rand's abilities, she was always worried by him and the threat he represented. Yet another feather in the cap of the cleverest of the Foresaken.