I tend to agree. Having gone through a full undergraduate and graduate physics program, and having met more than a few Nobel Laureate level physicists, I don't think I've met a single one that could go this fast. This is 5 to 6 years of just concentrated college-level physics, to say nothing of all the mathematical prerequisites.

As a recently minted theoretical physics PhD, I feel rather the opposite way on this. The vast majority of Nobel laureates still went through the usual university progression, which isn't at all designed to cater to the smartest students, but rather to ensure that a substantial part (~15-20% or so in my program, but this varies greatly) of the student population can actually graduate and do at least some research work afterwards. Notwithstanding the actual thesis research, I feel like my program could have easily been compressed by a factor of at least 2x (dispensing with much of the repetition that goes into making sure most people can do the exercises and internalize the concepts) without compromising the final state of my education.

Furthermore, if your goal isn't to do research work but rather to be able to follow along an average research article using the basic framework of QFT, you can also cut out much of the lab work. Susan is clearly considerably above average in intelligence and a quick study, and I'm impressed by her perseverence, but I don't think this is at all beyond what any good theoretical physicist could have done. It's just that they went a different path, going through the university system, a path with its own advantages, but brevity is not among them.

In spite of Susan, seems you're hell for leather determined to set low levels on people's expectations. Albeit in the physical domain (actually it's more restrictive for reasons of actual capacity unlike mental activity)https://en.wikipedia.org/wiki/Four-minute_mile has something to say on the subject.

There is something to be said for realism. The four minute mile didn't just topple for psychological reasons. It happened due to the development of better strategy (pacers), and continued to drop from there due to better training, better track materials, better shoes. The idea that it was purely a mental barrier is popular mythology.

That is definitely 5-6 years of study, because QFT is not taught in undergrad level in most cases.

her IQ could literally be one in a billion rarity