Sidebar2 not showing up in admin Widget page (2.8.6)

I added a sidebar2.php file so that I can have a different sidebar for a specific page of my site. When I am in the admin panel and I got to Appearance>Widgets, though, I am only able to add/remove widgets to my main sidebar. The second sidebar isn’t anywhere or the page and I can’t find a way to add it to the page.

I am using WP 2.8.6. All the searching I have done to find an answer for this has turned up answers using a previous version of WP in which you could simply select a different sidebar from a drop-down menu. My version has no drop-down menu.

This has got to be simple, but I’m not seeing it.

Thank you.