In all honesty, she probably won't take it seriously. She isn't attending because she wants to quit drinking; she going because she has to in order to stay out of jail.
I know that's not what you want to hear, but maybe hearing it will keep you from getting your hopes up. Considering her recent behavior and the things she has said to you regarding it, the chances are better than good that once she's free of her legal obligations, she's going to go right back to "having more fun" than she's ever had in her life.