Add Third or Footer Navigation Menu to Genesis Child Theme - https://amethystwebsitedesign.com/add-third-footer-navigation-menu-to-genesis-child-theme

functions.php

<?php
// Remove the line above when adding to functions.php

// Add theme support for new menu
// Add New Footer Menu; Keep Primary and Secondary Menus
add_theme_support ( 'genesis-menus' , array ( 
	'primary' => __( 'Primary Navigation Menu', 'genesis' ),
	'secondary' => __( 'Secondary Navigation Menu', 'genesis' ),
	'footer' => __( 'Footer Navigation Menu', 'genesis' )
	) );

// Add footer menu just above footer widget area
add_action( 'genesis_before_footer', 'amethyst_footer_menu', 9 );
function amethyst_footer_menu() {
  
	genesis_nav_menu( array(
		'theme_location' => 'footer',
		'container'       => 'div',
		'container_class' => 'wrap',
		'menu_class'     => 'menu genesis-nav-menu menu-footer',
		'depth'           => 1
	) );

}

// Add attributes to markup
// http://www.rfmeier.net/using-genesis_markup-with-html5-in-genesis-2-0/
add_filter( 'genesis_attr_nav-footer', 'custom_add_nav_footer_attr' );
function custom_add_nav_footer_attr( $attributes ){

	 // add role
    $attributes['role'] = 'navigation';
        
    // add itemscope
    $attributes['itemscope'] = 'itemscope';
    
    // add the site navigation schema
    $attributes['itemtype'] = 'http://schema.org/SiteNavigationElement';
    
    // return the attributes
    return $attributes;
        
}

style.css

.nav-footer {
     background-color: #333;
}

.nav-footer .genesis-nav-menu a {
     color: #fff;
}

.nav-footer .genesis-nav-menu a:hover {
	color: #e5554e;
}