They should definitely renegotiate ("complain") if they're not being paid a fair market rate... Comparing "relative to the world median" is just absurd, the comparison can only be to others in similar roles/locations.
Is she $200k, $400k, or more? Potentially line managers in big companies could be earning more than any of those numbers.
Is she $200k, $400k, or more? Potentially line managers in big companies could be earning more than any of those numbers.