Hook widget area for Instagram feed before footer.

functions.php

<?php
//* Do NOT include the opening php tag

//* Add Instagram widget before footer
add_action( 'genesis_before_footer', 'instagram_feed_widget' );
function instagram_feed_widget() {

	genesis_widget_area( 'instagram', array(
		'before' => '<div class="instagram"><div class="wrap">',
		'after'  => '</div></div>',
	) );

}