It is?! Of course the alleged victim has something to gain. Maybe I don't understand your post.
The alleged rape took place in a house that is owned by a wealthy university.
The alleged rapists are all white lacrosse players who as a rule are far more likely to come from affluent families than say football or basketball players.
The strippers knows that if she can somehow get enough people to believe it is true, that she will get a book deal or TV mini-series. She also has probably been told that if she files a lawsuit against Duke that they may actually settle rather than go to trial and keep this in the public eye. And if any of the alleged rapists are from wealthy families, she may get settlements from them simply to keep their names out of the papers.
Basically the stripper has everything to gain and nothing to lose.