JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <body>
        <div class="parent"></div>          
    </body>
</html>

CSS

.first_child
{
    display: none;
}

JavaScript

var parent = $(".parent");

$('<div class="first_child">first</div>').show().appendTo( parent );
$('<div>second test</div>').hide().appendTo( parent );