Backup Database before proceeding with the below.
Step 1: Create a new administrator.
Step 2: Fill in the required information. Use a different email for the new user. At the Role drop down select Administrator. Once done, click Add New User. The new admin will appear in the Users list.
Step 3: Log out and log in as the new Admin (Cassandra).
Step 4: Once log in, navigate to Users and hover your mouse over Daphne. You will see the option 'Delete' directly under the Username Daphne. Click on Delete and you will be prompt to select to either delete all content or attribute all content to the other Admin. Once you have selected, press Confirm Deletion to remove the Admin Daphne.
That's it. You have created a new Admin for your WordPress.