In reality  , nora wanted to infuse fear in yukine's mind , as she was trying to remove all yato's connections which connect Yato to goodwill. 
   <p><br>  Basically , she wanted to break yato's connection with yukine , him being yato's (yabko's) exemplar .She was continuously trying to make yukine leave yato (in fear) , so that she can awoke the previous yato , who's intention was to kill. </p>
  <br><p> As that would have left yato in enraged and mentally weak state(easy to control) that the death of yukine (which could have resulted in fall of yato). </p>