If any of the above mentioned are not high enough in the chain, it doesn't matter much.
You could have a ton of support, but if it's not at the C Suite level, it's probably not going to help unless they are very influential, which some are.
This is where understanding the internal politics and culture of your organization are paramount.
Talking to someone else who is just filling a seat isn't going to get you anywhere, but I guarantee that there are people in the organization who have influence with the ultimate decision maker(s).
If the employee is considered valuable then there is room to maneuver (not demand or even negotiate). And by valuable, I mean not easily replaced, well liked and respected by co-workers, clients, managers, and can be expected to thrive in an elevated role that would justify a bump in pay.
Best way to do that? Can this be tied to increasing revenue, profit, or sales? If the answer is yes, then there is a strong case if the decision maker can see it too.
If this is just about I'm moving more paper than I used to, then it's likely not going to succeed given the existing denial.
Getting more done with less is the manager's job, something that would suggest a raise is in order. It's still called capitalism.
That said, if she is unhappy with her work, company, compensation, or feels there has been an irreversible change in the employer/employee relationship, it's time to look elsewhere.
Not everyone will be happy at work, it's called work, but I wouldn't recommend anyone blindly stay in a bad situation.
Forgot to add this. That old position shouldn't be mentioned at all. It was deemed too expensive and expendable for a reason. Not part of the conversation you wish to have.