Use this code snippet to display a product attribute on the product page in WooCommerce on child sites.
Snippet Type
Execute on Child Sites
Snippet
add_action( 'woocommerce_single_product_summary', 'display_size_attribute', 5 );
function display_size_attribute() {
global $product;
if ( $product->is_type('variable') ) {
$taxonomy = 'pa_size';
echo '<span class="attribute-size">' . $product->get_attribute($taxonomy) . '</span>';
}
}