Hmm, Rand was able to defend himself against Moridins attacks. Granted he used Callandor when he did but that only meant extra strength. I do not know how it is possible to deflect TP attacks when you cannot sense them coming but then I don't know how any channeler can defend against attacks of the opposite gender either. Somehow it must be possible to do this or Rand would have been defeated at the end of the 3rd book.

My original idea was that Cadsuane would not even know to try to do this until it was already too late. It has however been pointed at me in this thread that we don't actually know with certainty if she has a ter'angreal like the foxhead. Still, she might still get burned by relying on her ornament that detects saidin and think Moridin is not channeling when he is.