How do I disable right click acting like a left click as well?

[Ama_Hamada]

So when she left clicks, it acts like a right click. Ok.
The first question to ask is does the right click act as a left or right click. If the right click is also acting like a right click, that does indeed point to a physical problem with the mouse.
If Right click is acting as a left click, your friend needs to go into the Mouse Properties and make sure that "Switch primary and secondary buttons" isn't checked. That will swap the functionality of those keys.

I haven't seen anything in the character configuration, system configuration OR the Keybinds menu that would change the mouse buttons functionality.
Also can you tell us if this issue FFXIV specific or occurring in other programs? This really is sounding like a mouse issue so far

Just ffxiv, I guess I left that part out, weird I thought I said it.