Very few people are too “advanced” to be challenged by a sufficiently difficult undergraduate degree, ridiculous thing to say imho, I went to a UK university this decade and I can give you a laundry list of issues more significant than “exceptional students being slowed down”.

This woman is undoubtedly exceptional. But we don't know how exceptional, because she's an outlier, educated using different methods.

We have no idea how many other people would achieve something similar with a similar background. Personally I'd bet almost anything it's a larger number than most people expect.

I'd also be surprised if she doesn't already have a pretty solid background in undergrad-level math.

The irony is she's actually more typical than not. Universities in the past were open to giving unusual talents special treatment.

Historically, the idea that everyone must follow the same path on the same timetable is unusual.