wayward sister

Hi ims. Need a bit of advice. My sister seems to be on a downward spiral. She has two kid. The youngest being 3 months old. For the past 7 years she has been behaving like a wayward teenager,(shes 27 ) drugs tantrums when you say anything and lots of alcohol.she got pregnant with her first and seemed to settle down. Fast forward two year's and shes at it again. Anytime anyone brings it up with her its "poor me" everyones picking on me. No accountability. We tried getting her proffesional help but she didn't stick to it as she believes nothing is wrong with her behavior. Even the physc doesn't think its depression but rather just a bad attitude and its who she is so unless she wants to change, theres nothing he can do. She once again got pregnant but this time didn't settle down. Still drank and smoked pot throughout the pregnancy and even seemed proud of it. Dcp have been contacted on numerous occasions but because the kids are clothed and fed, nothing has been done. Thats because our parents stop over daily to make sure they are. shes posting on facebook about getting drunk ect while having her kids with her including the baby. Im truly scared something is going to happen to the kids as she easily drinks1-2 bottles of spirits. Will post pics of empty bottles,call me rolling drunk ect. I live 5 hours away otherwise id just go get the kids. Im at a loss at what ti do or try. Please help sisterhood. I dont want to lose my sister or the kids