Follow the tutorial video 16
www.jms2win.com/tutorial#jms12x-16
The sharing of users is something that can only be done when you create the slave site.
Once a slave site is created, you can no more modify it as the DB and MySQL tables are created.
This require to use MySQL 5.0 or higher and have MySQL user privileges.
When you follow the tutorial 16, the expected result is that the MySQL tables for the users, sessions and other are displayed as a link and not as a physical table.
When you create the JMS template rule for the sharing, you have to open the "sharing" tab and select which extension you want to share.
Once the JMS template rule is defined, you can use it to create your slave site.