Rebellious niece; Rehab or not?

My name is Sierra. I have two daughters - Alison, 10 and Gabriella or Gabby, 5. My husband - Noah - and I have always instilled powerful values in our daughters: No smoking, drinking, or drugs, and stay a virgin until you're around 16-18, but it would be good to wait until marriage. Anyways, our family has just been a quiet little Christian family in Eden Prairie, Minnesota for the past twelve years. Everything has been going PERFECT. Until my niece - Chloe - showed up. She's been kicked out of my sister's house, my brother's house, my Mom and Dad's house, and all ten of my cousins' houses! Chloe is fourteen and has been being kicked out of houses since she was ten. The whole kick-off of it was when she had a miscarriage and she also went to jail for getting drunk at a club where she had somehow obtained a fake I.D. all while she was merely ten years old. My daughter's age! In fifth grade! I just don't understand how someone of that age would even know where to get a fake I.D. Back to the topic of my concern. She has been here since June fifth, and already she has brought home several men - who are all clearly over drinking age. I've also caught her smoking weed, on some sort of painkiller, having , and drinking. Don't get me wrong; I have tried to punish her. I've taken away her phone, forbidden her to go to her friends' houses, taken away all means of communication with her drug supplier, and I honestly have no more options left but one. Which is where my dilemma occurs. I know for a fact that Chloe's constant drug use and ual activity are affecting Gabby and Alison; Last week they asked what a blow*** was! They are too young to be learning all of these ual terms, and I'm afraid that Chloe will make them try something that they're not ready for. The only thing I can think of to do with Chloe is to send her to a rehabilitation center until she's a legal adult. I've suggested this to my sister many times in the past, and two of those times she told me to leave it up to Chloe's current guardian. I let it drop then. Now I'm wondering if it would be alright to tell my sister that if she doesn't remove her daughter's bad habits from my household and my family, since it contradicts our personal values and moralities, or I will show the police Chloe's illegal possessions and have her sent to Juvenile Hall. I know it sounds harsh, but those are the only two places she can go now. No one will be able to contain her besides professionals, and she's been kicked out of everyone's home that she possibly could be kicked out of. What should I do, and is it alright to tell my sister that or should I sit her down and talk to her about my troubles with Chloe firsthand?