JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.8.1/jquery.validate.min.js"></script>
<form id="myForm" name="myForm" method="post" action="" >
    <input type="radio" name="checkAge" value="adult" onclick="$('#minorRequisites').hide();" />Adult<br/>
    <input type="radio" name="checkAge" value="minor" onclick="$('#minorRequisites').show()" checked="checked"/>Child<br/>
    Name <input id="name" name="name" type="text" /><br/>
    <div id="minorRequisites">
        Age <input id="age" name="age" type="text" /><br/>
        Height <input id="height" name="height" type="text" /><br/>
    </div>
    <input type="submit" />
    
</form>

CSS

label {
    padding: 0px 4px;
}

JavaScript

$(document).ready(function() {
    $("#myForm").validate({
        rules: {
            name: "required",
            age: {
                required: "#age:visible"
            },
            height: {
                required: "#height:visible"
            }
        }
    });
});