I would recommend that she choose do to whatever she is most interested in. I am not sure how pharmacy schools work, but I know for med schools you don’t even have to major in a science as long as you take some science classes (Bio, Chem, Physics, O Chem). I am planning on applying to med school, and I’m an anthropology major/psychology minor.
If the extra $10000 would make a serious difference for you, that is something to consider. But I wouldn’t recommend studying something for four years (especially something that is very challenging) unless you are genuinely interested in it. She shouldn’t let the possibility of having a somewhat lower GPA deter her from doing engineering if that is what she wants to do. But, to my knowledge, being a Biology, Microbiology, Chemistry or Chemical Engineering major isn’t going to significantly impact her chance of getting into med school.
In short, she should do what she wants. If she enjoys what she is studying, she is more likely to be engaged and get higher grades anyways. One major isn’t going to give her an advantage over the other. It is no longer true that all pre-med students are Bio majors, or even that they are science majors. If she isn’t sure at this point, I would recommend talking to a pre-health advisor and taking introductory courses (like Bio, Chem, etc) and other general education requirements that are universal between the majors, and then make a decision after a semester or two.