Jen, here's my honest opinion. As someone who has had step parents walk in and out of my life like teens do burger joints, I know what kinda influence they can have. The kids dont see them so much as parents as much as they do friends. She's gonna get hounded by her biological parents enough as it is ontop of already feeling like a waste of life for fucking up. Perhaps step in and kinda be almost like a sister and try to help her out. What I'm going through isnt quite as bad as her situation, but regardless, I feel like shit everyday and being away from home right now still at school...I dont want to go back home. I dont want to see my dad. She's probably feeling similar to me. And you, someone whose been through it 3 times, try to talk with her, try to show her why its worth it to pick up her socks and try. I remember when my dad was mad with me in my earlier teens, my step mom would talk with me in private without my dad and really try to connect with me...talk heart to heart and not try preach but kind of show me whats best. I really liked her for that, and she got me through some rough times.
My dad and I talked on the phone, he and I are different now. He no longer talks down to me, we see eye to eye. Any decision that I want to make is my own. If those decisions fuck up my life, so be it. But he told me, "Son, you have to understand what this schooling means. It's a few years of hard work. THATS IT. Forget about partying now, that will come later. You can either work hard now and be set later on in life or you can party now and forget about school and have to bust your ass doing hard labour or some crap ass job that you dont want for the remainder of your life. We are talking about 4-7 years of bootcamp as opposed to the rest of your life." Thats not saying that there is no work after school, but compared to what you'll be faced it with, its the way to go. But I now know that nobody is gonna wait up for me if I fail, and neither will anyone for her...you really gotta get that into her mind or else she is really gonna suffer down the line.