Immunisation and password protected users

My sister's account on the computer is password protected and It means that she isn't getting immunised. Is there a way of solving this problem?

Admin accounts can immunize other user accounts regardless of their passwords. This function is disabled when the machine is a terminal server though (or you've specified nouserhives). If you want to force-trigger Spybot-S&D to run seeing any other user accounts, you could add the parameter /allhives to its command line in its shortcut.