Warning: Attempt to read property "ID" on null in /home/u522501990/domains/readforlearn.com/public_html/wp-includes/media.php on line 2639
Since the gallery is rendered via a shortcode, you can try using do_shortcode() in footer.php. For example, assuming you want to output a gallery with an ID of 1:
<?php echo do_shortcode( '' ); ?>