pewc_filter_exact_children_validation_notice.php

<?php
/**
 * Filter exact children validation notice
 */
function prefix_exact_children_validation_notice( $notice, $label, $min_products ) {

	$notice = sprintf(
		__( '%s requires you to choose %s products', 'pewc' ),
		esc_html( $label ),
		$min_products
	);
	
	return $notice;
	
}
add_action( 'pewc_filter_exact_children_validation_notice', 'prefix_exact_children_validation_notice', 10, 3 );

/**
 * Filter min children validation notice
 */
function prefix_min_children_validation_notice( $notice, $label, $min_products ) {

	$notice = sprintf(
		__( '%s requires you to choose %s products', 'pewc' ),
		esc_html( $label ),
		$min_products
	);
	
	return $notice;
	
}
add_action( 'pewc_filter_min_children_validation_notice', 'prefix_min_children_validation_notice', 10, 3 );

/**
 * Filter max children validation notice
 */
function prefix_max_children_validation_notice( $notice, $label, $min_products ) {

	$notice = sprintf(
		__( '%s requires you to choose %s products', 'pewc' ),
		esc_html( $label ),
		$min_products
	);
	
	return $notice;
	
}
add_action( 'pewc_filter_max_children_validation_notice', 'prefix_max_children_validation_notice', 10, 3 );