I don't know, the school is being pushy about the kids figuring it out. They have college prep programs (so next year she could do medical science clinicals, veterinary science preparation, etc) , and most of her friends already know what they are doing. And she really wants to sort this all out, as she has a 4th year in college brother who still has no idea. Yes- I said a senior in college has *no* idea what he is doing when he gets out of college, and he told himself all through middle and high school that he would figure it out the way you listed above. The other problem is that she has a school she wants to go to that will combine her 11th and 12th grade years with college if she chooses a math/science career.
I see what you are saying, but I think there is just too much on the line to wait until then.