OK, I figured it out. Here is how to do it:
- activate the root account using Netinfo manager (assuming it is not already active)
- log out
- log in as root user
- open system preferences
- open intetrnation panel
- change language/input menu options as required
- log out
hey presto, the login window now responds to the new settengs.
Now my wife can log into the computer - up till now she has been rather confused by the dvorak keyboard layout running on a qwerty keyboard
Hope that helps someone out there!