Well, she is also extra retarded. When she saw him for the first time, he ran away from the guards, who yelled "Intruder, intruder!". Yet she saved him, because she thought he is the hero. (Too bad he is just an idiot.) Now she is convinced she made a mistake. That doesn't leave much options, does it? So...in the end he MUST be an intruder, but that escaped her mind.