Sister doing and dealing drugs and drinking?

Okay so my sister is 21 years old, and my family just found out that she has been selling drugs (pot) and doing them, she got kicked out of her Christian sorority for smoking it, and we also found out she has had a drinking problem for almost a year. She has blacked out driven drunk, has been selling pot for months, and she says she has no problem, yada yada yada. I want to know what I can do or what my parents can do. My parents pay for half of her school all her rent, gas, food, etc. Oh and she has "money trouble" with all that. But I feel like my parents are enabling her. So what can any of us do. I am just pissed off royally! I want nothing to do with her but I believe in God and forgiveness so how can I forgive her but still let her know it is okay. And when she comes around do I bail, do I ignore what??? I feel like if I act naturally then she'll think everythings okay. And what can my parents do because I feel like they're doing nothing at all.