Did you put your name in originally or did someone at Tesla set it up for you? I'm guessing someone else set up your profile and abbreviated your name.
You should be able to just tap on your name and then at the bottom, choose the Driver Profiles Settings option. It will take you to a screen where you can add, delete or edit profiles. I just confirmed all of our driver profile names were being displayed correctly. I even created a Bethany profile and it displayed correctly.