Send/Include 'name' field to Mailchimp using API with AJAX
Going off of the Mailchimp listSubscribe function documentation found here:http://apidocs.mailchimp.com/api/1.3/listsubscribe.func.php
You just need to create a merge_vars array that will hold any additional fields associated with the subscribing email. For example:
$merge_vars = array('FNAME'=>'first name', 'LNAME'=>'last name');
And then just pass that array in your $data.