There are 2 Indian girls that were always mentioned in the books, and they factor into the 4th book. One of them is Harry's date to the Yule Ball.
I don't remember them in the books, but I'm sure you know what you're talking about. I guess, when I read books, I don't notice what ethnicity the people are. To me, it just seemed to be a little too PC to be adding minorities just for the sake of appealing to the new immigrants to Britain. Not that I see any problem with it; it was just unexpected for someone who doesn't pay that much attention to such details. Come to think of it, there's a lot of different countries that pop up in the book, including Cho and some Russians from another school.