Thank you for getting back to me, Keymaster.
I have resolved the issue.
For anyone else who might need help with this:
1. Appearance -> Menu -> Links -> URL
2. Type in the URL for one of your site’s authors.
Ex: site.com/author/authorusername
Ex: BestMonkey.com/author/steve
3. Click “add to menu”
4. Drag and move around the Menu Structure area
Possible problems:
Usernames with spaces must be inputted with dashes. Ex: John-Pumpkin
Once again, thank you Themonic-Support.