Modifying the output of shortcode in child theme

I am trying to change the way the testimonial shortcode displays (created via page builder) to have the name and position on top of the actual testimonial.

I could do this in the parent theme by modifying the output order in the /config-templatebuilder/avia-shortcoldes/testimonials.php file.

My question is: what is the best, most WP friendly way to include this modification in the child theme so that it doesn’t revert back to default display on theme update?

Do i need to re-create the /config-templatebuilder/avia-shortcodes structure or can i do it directly in child theme’s functions.php?

The modified code looks like this:

function av_testimonial_single($atts, $content = "", $shortcodename = "")
			{
				// ...

	//final output
				
				$markup = avia_markup_helper(array('context' => 'person','echo'=>false));
				
				$output .= "<div class='avia-testimonial {$class}' $markup>";
				$output .= "<div class='avia-testimonial_inner'>";
	if($grid)   $output .= $avatar;
				
				$output .= 			"<div class='avia-testimonial-meta'><div class='avia-testimonial-arrow-wrap'><div class='avia-arrow'></div></div>";
	if(!$grid)  $output .=  $avatar;
				$output .= 				"<div class='avia-testimonial-meta-mini'>";
	if($name)	$output .= 					"<strong  class='avia-testimonial-name'  {$markup_name}>{$name}";
if($subtitle)	$output .= 					"<span class='avia-testimonial-subtitle'  {$markup_job}>{$subtitle}</span>";
    if($link)	$output .= 					"<span class='hidden avia-testimonial-markup-link'  {$markup_url}>{$link}</span>";
	if($link)	$output .= 					" – {$linktext}";
				$output .= 				"</div>";
				$output .= 			"</div>";
				$output .= 		"<div class='avia-testimonial-content' $markup_text>";
				$output .= 		ShortcodeHelper::avia_apply_autop(ShortcodeHelper::avia_remove_autop($content));
				$output .= 		"</div>";
				$output .= "</div>";
				$output .= "</div>";



				if(avia_sc_testimonial::$counter == avia_sc_testimonial::$columns)
                {
				    $output .= "</section>";
				}

				avia_sc_testimonial::$counter++;
				if(avia_sc_testimonial::$counter > avia_sc_testimonial::$columns) { avia_sc_testimonial::$counter = 1; avia_sc_testimonial::$rows++; }


				return $output;
			}