Is she meant to be kinda ditzy, or does the author know nothing about assassins except they walk quiet, move fast, talk aloud in stupid code words, and kill people? What about blending into the surroundings, becoming just another face in the crowd, covering your tracks, always be on your guard, operating at night, and most of all, not wearing inexplicable bandages when the guy who's already suspicious of you bursts through the door?
Sorry, assassin is my favorite 'fantasy profession' and I get pissy whenever it's not handled properly.