Well I think that's the first time I've seen in a manga or an anime someone realizing that when they travel to Hawaii they're in fact entering the US of A. Usually they seem to treat it as if they were going to a country called Hawaii.
I know she's a foreigner, but what if this is a hint that she's actually from Japan. Then again it could be just manga logic that someone as airheaded as Shiori is able to speak Japanese.