...Simple: Show her a video like this:
I know what you're going to ask: What's so amazing about some Finnish singing show? Well, not the songs themselves (though I must admit I am a fan of both Kaija Koo and Heart).
Now, I truly do admire how casually bi, tri, or even quadrilingual so many European countries can be. And I've known that countries like Finland have this especially, as Finnish isn't spoken widely outside its own country. I know this, but since I don't experience it every day, noticing it can sometimes be a shock.
For me, to see everything in the program (singers, lyrics) instantly switch effortlessly from one language to another was both shocking and, well, awesome. The thing about America is that you just don't see that here. Not on that scale. A whole audience and TV production crew would not just slip into a language other than English with no visible problems.
So yes, I'm kind of being a starstruck little language nerd right now. Sue me for it. Also, I would recommend this video even if you don't care what language they're singing in, just because "Tinakenkätyttö" and "Alone" are wonderful songs.