My guess is, if she still wanted the listing, you would have received payment or at least would have heard from the customer by now. I would send her one final message saying payment must be received within a very short time (like 24 or 48 hours) or the item will be relisted. I included in my shop policies that if payment was not received within a certain time (3 days, I think), the item would be relisted. You might want to add such a policy to your shop policies so you can avoid this problem in the future.
Sorry this happened to you, but live and learn, right?.