Hi Paul Scott,

I am not seeking "personal happiness".  I do seek something that has original thought. But admittedly, anything in that vein could open a candidate to attack.  But I'll take your challenge. 
Of course one has to show solidarity with the European people. And offer cooperation. Outside of that, one could remind people that terrorism is a perversion of the Muslim religion and the the Muslim world, including that the Saudis, must do more to help combat. 
She could note that since 9/11 our deadliest terror attack has been 14 killed by radicalized Muslims living here.  While this is alarming, it also points to the relative success our country has shown combating another 9/11. But that would downplay the fear. 
Instead she said we must work harder.  Yep, got that.