I worked with International students at a large university, and we usually had an orientation week where we took them out into town for different things. They were FLOORED by the Wal-Mart SuperCenter (imagine 60 students from around the world riding a bus to Wal-Mart and being told they have two hours to buy their sheets, pillows, toiletries, groceries, etc. I was asked by one student if this was the "black market", as the prices were so cheap.). Most of the Int'l students came from larger cities, which is natural since that's where the Universities are, and had been exposed to American chains like McD's, Burger King, Wendy's, Pizza Hut, and other Fast Food places. We took them to the beach and stopped at a seafood restaurant, which had a good variety on the menu, and everyone loved it.
Where in Austria is she from? From the time I spent there, I remember that I had no trouble finding things to eat that I like, and I am a very picky eater. Lots of meat-and-potato dishes, which won't be hard to find here!
I would just be sure to ask at some point in the first couple of days what kind of things they like to eat, if they have allergies, what is their favorite restaurant/food.
Oh, and our international students really liked the Golden Corral buffet.
Have fun!