Two things that I have learned by watching very gifted children (including a small number that are obviously in the top 1%): Just because they can do it, does not mean that they can do it without a lot of stress. Also, kids can reach a breaking point.
I don’t see any reason to take four AP classes as a freshman, or even to take any AP classes as a freshman. I have attended highly ranked universities and have known many students at highly ranked universities. Each of them needed to find the right level to push themselves. However, they got to attend highly ranked schools by doing whatever they did very well, not my pushing themselves to the point of collapse.
It is not easy to find the right point where a gifted child is pushed the right amount. I definitely would watch my child carefully, and let her know that she does not need to push herself this hard.