How to change a MacBook’s "main" login/user?

I got a new (reconditioned by Apple) MacBook for my girlfriend. When it arrived, I went through the setup process and created my account, and then created her account afterwards. Both have admin privileges.

If she shuts down and reboots, it only ever asks for my login. She cannot login unless I login first and then we do a switch-user.

She uses it more than me, so my thought is that she should have been the one to run through Setup Assistant.

What is the recommended way to fix this?

I’m a bit chary of simply removing .AppleSetupDone

  • Will that wipe the existing user’s home directory (we would want it to have the same name) ?
  • Will that actually "reset" who the default login is?
  • Is there some other reason why she cannot login from a reboot, despite being admin?

I’ve checked the following questions, but it is still not clear to me exactly what I should do:

  • How to change boot login
  • How can I create a new macOS user using a pre-existing home directory?
  • How to change the main user name of a used MacBook on macOS 10.13?