Empty space on right of Sparkling Menu

I’m enjoying using the Sparkling theme for my site (which has not been posted yet, I am using MAMP to set it up on my computer).
The other day I noticed a blank space on the right hand side by the menu. When I have the window set to a computer browser size, there is always a scroll bar on the bottom of my page (so that you can always scroll left and right) no matter how I resize the window. I would like to get rid of this extra empty space.
The plugins I have installed are Backup, Media Author, Media File Manager, Wordfence Security, and Wordpress Importer. I am using an old OS (10.6.8) but I don’t think that this should have any impact?
I’ve attached a screenshot of the window with it scrolled to the right.
Thanks for any thoughts anyone has about this!

I’m not sure why this is the case but I was able to resolve this.

My child theme contained:

#footer-area .container.footer-inner, .footer-widget-area .footer-widget {
  width: 100%; 
  margin: 0; 
  padding: 0; 
}

When I reduced the width to less than 100%, the empty space and extra space (and scroll bar extension) went away.

Awesome great to see you got that resolved.

Please advise if you have more questions.

Have a fantastic day!