We'd like to change our username from healthyfamilyexpo to healthyfamilymedia. Is this possible?

As requested, I have changed your username from healthyfamilyexpo to healthyfamilymedia. 

Please note that if you are using custom URLs to your forms, it will no longer work as the username has been changed. You need to change the custom URL with your new username. You can check this guide on How to Create a Custom URL of a Form.

Let us know if you need further assistance.