There is no way to take advantage of all of the possibilities in college. In fact, it is a sign of a good school that there are too many good opportunities to exhaust them all. I agree it is not wise to “load up” on the chemistry courses. There is nothing wrong with not doing a semester broad and her chances to enjoy experiences abroad are not limited to college.
It is better that she found her passion and is able to do the chemistry major at her school than to major in another field just to do semester abroad.