First of all, your girl friend has not even started her education as a physiotherapist; so how does she knows physio's know more? Next a band 5 tells what Salary scale you're in thus it cannot be different for a physio or a nurse. Third: a physio does not work (in general, unless highly specialised) with life threatening issues. The world would survive without physio's not without nurses. (e.g. florence nightingale)
If she really is in the money she ought to choose a different occupation than physiotherapist who even if he works in a private practice still has to work hard for the money. unless he/she chooses to attach every one to a device and hands out a sheet of paper or has many employees he/she pays 30% of the money the employees make (on the contrary if she choses to go on the continent she might up in between 65%-75%) for every patient she sees. The rest goes to the practice. (I might be wrong, some practices might pay more).
To me, a physiotherapist, I would feel it would be fair to pay people what they are worth: we can do away with bankers, politicians but not with teachers, nurses and doctors, farmers. Which shows actually how unfair payment can be.