Child theme does not take on horizontal menu bar up top

Greetings.

This is regarding my org’s site.

I made a child theme for my org’s current theme b/c I would like to make some minor adjustments. I have put no theme changes in the child, and have uploaded it just to check it out.

The child picks up everything but the horizontal menu bar up top.

When I look at the code using the developer tools in Safari I can see that there are a few stylesheets – but they seem to come from a couple of the plugins we had installed. There is one called supersized that I don’t see when I look at the editor section on the WP dashboard – however I do see it when I look at the files on the server.

In the files on the server, there’s the usual style.css, there’s a stylesheet for Internet Explorer, and then there’s a supersized.css one in its own folder. It does not seem as if the supersized has anything to do with the menu – it looks more like a slideshow mechanism.

I also installed jetpack and the Yoast-recommended plugin “Manual Control for jetpack” so that perhaps I could use their edit css to make my changes without having to figure out what to do about the child theme and the menu. But nothing I do in edit css makes a dent.

I really don’t want to change the original code. Does anyone have any suggestions?

Any help much appreciated.
Lawrence