Why do people always judge my fiancee when they ask where she is from?

Very simply, the brain is a lazy lazy organ. Rather than using all it's power all the time it likes to take shortcuts to get us through life without thinking too much. How it does that is by creating little rules that it then generalised to a number of similar but different situations. So if you meet someone from Ireland and you've heard lots of Irish jokes your brain will probably ume that the person is fairly thick. As such when people meet your partner and she tells them she is part Iraqi, they having watched the news once have come to the conclusion that she is some sort of bomber. It's simply cause their brains are lazy and having to actually get to know and understand your partner as a good person would require time and thinking.