If you feel that the group is still active and another member would be a great owner, you can transfer ownership of that group to her.
Here's how to transfer ownership of the group:
1. Go to your group's homepage.
2. Scroll over the 'More Admin Tools' link at the top of your groups page.
3. Click on 'Member List' from the dropdown menu.
4. Search for the member that you want to transfer the group to.
5. Promote the member to 'Head Admin' using the update role and title link.
6. A link labeled 'Transfer Group Ownership' will appear.
7. Click that link to transfer ownership.