My D has been set on becoming a doctor since elementary school. I once brought up the idea of a possible “backup” career in case she changed her mind and it did not go well. There is simply nothing else she wants as a career. I am well aware that she could still change her mind while in college. I have recommended to her and to other hopeful pre-meds to choose a school that does not admit by major and where changing majors is very easy, for this reason. While premed is still in their hearts, it may be impossible for them to pick a different path, so the flexibility is necessary.
My guess is that if D does change her mind she might very well go into high school science teaching. I think it would suit her personality.