Grace probably doesn't even begin to comprehend the complexity of producing an effective vaccine. Some of the best scientific minds in the world are trying to find an good vaccine. But hey, guess she is an expert.
While I think a vaccine will eventually be produced (though it may not be 100% effective or a magic bullet), and while I'm not sure of it, I've begun to suspect Fauci is deliberately being misleading about the timetable for producing a vaccine. Given his history of lying (admittedly about the masks, and suspectedly about the length of the lockdowns), I think he is painting a rosy picture to try and keep people in line (knowing if he were to say summer 2021-late 2021 people would just say f this and rebel but if it's only a few months they are more likely to hold it together for longer). We already know despite the AAP paper, his preference leans towards keeping the schools closed.