Mobile Responsive Header Menu for Genesis Sample Theme --- http://amethystwebsitedesign.com/mobile-responsive-header-menu-for-genesis-sample-theme/

functions.php

<?php
// Note: Add only code below to your functions.php

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

	//Add mobile button script to Header Right widget navigation menu
    wp_enqueue_script( 'header_nav_for_mobile', get_bloginfo( 'stylesheet_directory' ) . '/scripts/header-mobile-nav.js', array('jquery'), '1.0.0' );
}

header-mobile-nav.js

// Add this to a /scripts folder in your child theme

jQuery( function($) {
        'use strict';

	// Insert mobile menu before the Genesis Header Right widget navigation menu
	$( '<div id="header-mobile-menu">&#x2261; Menu</div>' ).insertBefore( 'nav.nav-header ul.genesis-nav-menu' );
	
	// Add .hide class to .nav-header .genesis-nav-menu to hide it for small screen sizes
	$( 'nav.nav-header ul.genesis-nav-menu' ).addClass( 'hide' );

	// Toggle Header Right widget navigation menu for mobile menu
	$('#header-mobile-menu').on( 'click', function() {
		$('nav.nav-header ul.genesis-nav-menu').slideToggle();
		$(this).toggleClass('active');
	});

});

styles.css

/* Add to the bottom of child theme styles.css */

@media only screen and (max-width: 768px) {

	/* Start Header Right Widget Mobile Menu Navigation
	 --------------------------------------------------- */

	.nav-header .genesis-nav-menu.hide {
		display: none;
	}

	#header-mobile-menu {
		color: #999;
		cursor: pointer;
		display: block;
		font-family: Lato, sans-serif;
		font-size: 18px;
		font-size: 1.8rem;
		height: auto;
		line-height: 18px;
		padding: 20px 16px;
		padding: 2rem 1.6rem;
		text-align: center;
		text-transform: uppercase;
	}

	#header-mobile-menu:hover,
	#header-mobile-menu:focus,
	#header-mobile-menu:active {
		color: #333;
		display: block;
	}

	.nav-header .genesis-nav-menu .menu-item,
	.nav-header .genesis-nav-menu a,
	.nav-header .genesis-nav-menu .sub-menu {
		border: 0;
		text-align: center;
		width: 100%;
	}

	.nav-header .genesis-nav-menu .menu-item > .sub-menu {
		clear: both;
		margin: 0;
		opacity: 1;
		position: inherit;
		width: 100%;
	}

}


@media only screen and (min-width: 769px) {

	/* This makes the header nav menu normal again when the browser window expands */
	.nav-header .genesis-nav-menu { 
		display: block !important; 
		height: auto; 
	}

	/* Hide Header Mobile Menu Button */
	#header-mobile-menu {
		display: none;
		height: 0;
	}

}