Should I tattle tale on this hard quiz?

Okay so today in Social studies, my teacher gave me and others a chance to take the current events test for academic bowl. So most of the people who took it didin't get it done. So my SS teacher told us to come and get our tests at studyhall. So at study hall, this girl (lets call her Lauren) went to go and get the tests from the teacher. We all finish and Lauren took the quizzes to the teacher. In homeroom she told me she cheated off MY very hard unpredicatble answers on that academic bowl test. Lauren is probaly the last person to ever know that Guantanno Bay is in Cuba! I'm really steamed at her because she cheated off of my 6 questions! Should i tell or not? If she gets picked to go to quiz bowl she won't know a thing about what we're answering questions about! IM STEAMED