The problem with the Arab thing is that Sara's father...also refers to Turkey as an Arab country and they say this in front of Turkish people like Amesh without anybody bothering to correct them.

This, plus all the other mistakes that the commenter pointed out further down her list (getting the word for "grandfather" wrong, deserts in Istanbul, almost none of the "Turkish" characters having names that are actually Turkish) makes me think it was likely more than a mistake by the PoV character.

Also, isn't this YA fiction? I'm not saying you should talk down to a younger audience, but isn't the device of an unreliable narrator a little advanced, if you're not going to bother to correct or make clear the errors? Since many non-Turkish children wont know the capital of Turkey, wouldn't having the main character make an intentional mistake for the sake of characterization go right over their heads?