Hello,
We replaced all your code from theme-child.js (it was not able to work) and added working code
jQuery(document).ready(function($){
var menu_switcher = $('.header-wrapper').find('.mobile-language-switcher').html();
var fixed_menu = $('.fixed-header').find('.menu-wrapper');
$(fixed_menu).after('<div class="mobile-language-switcher">'+menu_switcher+'</div>');
})
Now you should not worry about changing etheme.js and compressing into etheme.min.js in our theme. Menu switcher will be added without any worries just from your child-theme.
Regards