gallery small on screen

I have a new child theme. everything should be up to date. Hosted with Bluehost.

The developer used a sirius wordpress theme and embedded the Nextgen gallery in it. The problem I am having is that the gallery pages leave a lot of space at the bottom of the page and to the right of the gallery. In the album page it fills the page completely from top to bottom, but does not expand to fill the page to the sides. I cant find any settings to fix this and the developer could not either.

Where do I go to look for this fix. The site is http://www.dkwphotography.com/gallery

https://wordpress.org/plugins/nextgen-gallery/