add text to right side of logo - in hgroup?

I would like to add 3 lines of bulleted text to right side of the logo on this site:

I see that the social icon container(?) hgroup is about where I would like the text to go.
I used your a child theme and created the directory > library/structure/header-extensions.php

Then add in the code to the header-ext but nothing shows? Could you please explain what is the best way to add text into that space?



Using the directions here I was able to add the text into the header.

But since all the text modifications were made in the header-extensions.php in the parent theme’s library, how do I save these changes to the child theme?