How to add Voting to Child theme?

I’m tired of having to reinsert the <?php echo nggv_imageVoteForm($image->pid); ?> line everytime NGG has an update, but I can’t figure out how to make the change work in my child theme.

I’m trying this line in my Child’s functions.php file:
include( get_stylesheet_directory(). ‘/wp-content/plugins/nextgen-gallery/view/gallery.php’ );
… copying the directory structure in the Child theme (not sure if that’s necessary?).

Would it be better to use an action hook somehow? If so, how would that be done?

https://www.ads-software.com/extend/plugins/nextgen-gallery-voting/