Yes. Who else could have made the call?
So this answer is a bit surprising from you as you seem to rip holes in all theories presented here on WS. Yet you conclude that just because a call is made then there is no doubt that NC must be alive at that point. It seems that you are willing to discount all other possibilities that exist that can explain this call being made. I wonder how many on the jury would be inclined to believe that a voice call made from the home phone must also imply that NC made the call, thus she was still alive. I am only asking this in anticipation that the TWC detailed records will show this 6:40am as a voice call.