@amyor
First pick a major she likes, she will likely get better grades.
Then, what other careers would she be interested in, should med school not work out, for whatever reason. Would she still want to be a healthcare provider? Researcher? Financial analyst?
The good news is at some schools she doesn’t have to choose a major at first (although if it stays engineering she should apply directly to those programs/majors.)
I wouldn’t hesitate to choose some majors that some may tell you don’t have good career prospects. For example, I know many bio majors who are working in the pharmaceutical industry, making a good living with a bachelors degree. Bio major outcomes immediately post grad might show a lower than average salary, but that’s because there are lots of bio majors working for a couple of years after college as scribes or EMTs or CNAs to get more clinical hours so they are more competitive med school applicants.