WP: Conditional IE stylesheets from child theme

functions.php

<?php

add_action( 'wp_enqueue_scripts', 'child_theme_scripts' );
function child_theme_scripts() { 

    global $wp_styles;

     /**
     * Load our IE-only stylesheet for all versions of IE:
     * <!--[if IE]> ... <![endif]-->
     */
	wp_enqueue_style( 'my-theme-ie', CHILD_URL . '/css-ie/style-ie.css', array(), PARENT_THEME_VERSION );
	$wp_styles->add_data( 'my-theme-ie', 'conditional', 'IE' );
    
    /**
     * Load our IE version-specific stylesheet:
     * <!--[if IE 7]> ... <![endif]-->
     */
    wp_enqueue_style( 'my-theme-ie7', CHILD_URL . '/css-ie/style-ie7.css', array(), PARENT_THEME_VERSION );
    $wp_styles->add_data( 'my-theme-ie7', 'conditional', 'IE 7' );

    /**
     * Load our IE specific stylesheet for a range of older versions:
     * <!--[if lte IE 8]> ... <![endif]-->
     * NOTE: You can use the 'less than' or the 'less than or equal to' syntax here interchangeably.
     */
    wp_enqueue_style( 'my-theme-lte8', CHILD_URL . '/css-ie/style-lte8.css', array(), PARENT_THEME_VERSION );
    $wp_styles->add_data( 'my-theme-lte8', 'conditional', 'lte IE 8' );
    
    /**
     * Load our IE specific stylesheet for a range of newer versions:
     * <!--[if gte IE 9]> ... <![endif]-->
     * NOTE: You can use the 'greater than' or the 'greater than or equal to' syntax here interchangeably.
     */
    wp_enqueue_style( 'my-theme-gte8', CHILD_URL . '/css-ie/style-lte8.css', array(), PARENT_THEME_VERSION );
    $wp_styles->add_data( 'my-theme-gte8', 'conditional', 'gte IE 9' );
}