All she has to do is leave the group, there is a leave option. If she is an admin she should know that.
at 9:25 AM on Jan. 5, 2009
Here's how to remove yourself from a group:
Click the 'Groups' tab.
Click the 'My Groups' link on the left side of the page.
Go to the page of the group you want to leave.
Click the blue 'Group Settings/Leave Group' button.
Click on the blue button that says 'Leave Group'.