Hi David. The widget is loaded using a function in the parent theme. You need to copy that function to your child theme functions.php file:
function alx_load() {
// Load theme languages
load_theme_textdomain( 'hueman', get_template_directory().'/languages' );
// Load theme options and meta boxes
load_template( get_template_directory() . '/functions/theme-options.php' );
load_template( get_template_directory() . '/functions/meta-boxes.php' );
// Load custom widgets
load_template( get_template_directory() . '/functions/widgets/alx-tabs.php' );
load_template( get_template_directory() . '/functions/widgets/alx-video.php' );
load_template( get_template_directory() . '/functions/widgets/alx-posts.php' );
// Load custom shortcodes
load_template( get_template_directory() . '/functions/shortcodes.php' );
// Load dynamic styles
load_template( get_template_directory() . '/functions/dynamic-styles.php' );
// Load TGM plugin activation
load_template( get_template_directory() . '/functions/class-tgm-plugin-activation.php' );
}
Then change this line:
load_template( get_template_directory() . '/functions/widgets/alx-tabs.php' );
to this to load the widget from your child theme:
load_template( get_stylesheet_directory() . '/functions/widgets/alx-tabs.php' );
More information in the theme documentation.