a. Add this code in Child theme - Functions.php
add_action('widgets_init','mywplms_register_sidebars');
function mywplms_register_sidebars(){
register_sidebar( array(
'name' => 'My Bottom Footer Sidebar',
'id' => 'mybottomfootersidebar',
'before_widget' => '<div class="col-md-2 col-sm-4"><div class="footerwidget">',
'after_widget' => '</div></div>',
'before_title' => '<h4 class="footertitle">',
'after_title' => '</h4>',
'description' => __('Bottom Footer widget area / sidebar','vibe')
) );
}
b. Copy footer.php from parent theme into your child theme and change "bottomfootersidebar" to "mybottomfootersidebar" in the footer.php file of child theme.
p.s: Moving to customisations forum.