"A humanities student"? She's a humanities student who had taken up through linear algebra! I have a CS degree and I never learned linear algebra in high school or college--I learned about the topic later!
The idea that a 200-level course should be unapproachable for an interested person with a stronger mathematics background than I have, with an ostensibly mathematics-based degree, is absolutely silly. I took 300 and 400-level classes in economics, in English, in history and philosophy. I never felt unwelcome or incapable.
> I have a CS degree and I never learned linear algebra in high school or college
Really? I mean, you probably did have linear algebra in high school, it was just "disguised" (you may not have seen matrices and vectors, but probably did solve linear equations of multiple variables). I'm surprised about the college thing, though. I thought every CS degree (in the US at least) required at least through linear algebra (linear algebra with applications, probably not linear algebra with proofs and theory).
The idea that a 200-level course should be unapproachable for an interested person with a stronger mathematics background than I have, with an ostensibly mathematics-based degree, is absolutely silly. I took 300 and 400-level classes in economics, in English, in history and philosophy. I never felt unwelcome or incapable.