Benefit Fraud?

I know someone who is commiting benefit fraud. She has been a right ***** to me but I don't know if I should report her. I mean being a gr is dodgy isn't it, no one likes a gr. I know revenge is sweet but what I'm scared of Karma. And why should I pay my taxes for that cow to live off but then again the government takes all our money from us, why can't we do the same to them.... hmmmm.....