A buyer on Ebay doesn't pay yet what to do?

I sold something $150. And she won bidding. Her feedback is only 1. At first, i didn't want to company with any buyers who got under 5 feedbacks. But found people on yahoo answers said its okey to let them buy as long as they will pay you. So i sent her invoice 2 days after she won and the next day, sent her a msg but nothing going on. Its been 5 days now..Do i have to report ebay?? Plss help.. Thanks a lot!