It doesn’t surprise me at all that a kid would learn a language on his own, but it would be nice to know the motivation.
I think what she is trying to say, and doing it badly, is that they are looking for authenticity and passion, not resume fillers. She can’t tell whether the kid is a resume filler or authentic.
I sense that Stanford and the other elites have moved on and refined their approach in the past few years. Her advice is dated. Gone is appreciation for a well-rounded kid (which btw many boarding schools have historically endeavored to produce). Spikes are where it’s at. Be great at academics AND something else. World-class dabblers need not apply. That kid she is reviewing doesn’t have a non-academic spike - an authentic deep interest in something. Dabbling in German doesn’t cut it.