I would send one more message saying if you don't get a response within 24 hours you'll cancel the order. That way there's no mistaking the time line. Also, if she paid through paypal, I'd send a message to her at her email address listed in Paypal. It could be that she hasn't signed in to see she has convos from you, and she might not have it set up to email her automatically when she receives messages through Etsy.