As I understand, when you want to make changes, you copy files from the parent theme into the child theme and make customizations in there, but after I copied contents of:
That’s not how child themes work or what they’re used for.
A child theme can replace a WP template and it can load additional code. Templates specifically are those files that are mentioned in the template hierarchy, and loaded using functions such as get_template_part.
You cannot replace arbitrary PHP files or assets this way, and while WordPress will load the functions.php of both the child and parent themes, it has no idea if they are individual files or if they load thousands of other files, or what their purposes are. They’re all loaded into the same melting pot of code along with plugins and WP core itself.
This means whatever you do in a child theme, your parent theme is still going to do what it’s already doing unless you modify that parent theme. Some theme authors might provide hooks and settings that let you change this, but they’re unique to each individual theme and developer, assuming the developer added them at all.
This means that overriding a widgets output is the same wether that widget is in a child/parent theme or even a plugin, there is no difference.
How To Override A Widget.
If you want to override a widget, it doesn’t matter if it’s in a parent theme, child theme, or plugin, there are two methods:
- Unregister the widget and register it again using your own copy that has modifications
- If the author of the widget has provided filters and hooks you might be able to use them to modify the widget. You will need to check the code or documentation as this is unique to each widget, and isn’t always possible.
This question/answer will help: How to override / customize existing Widgets?