Social - Swiv worries over her teen sister's heroin usage

[Venusia]

Swiv is really scared she may lose her sister. She's 16 and has an extremely addictive personality. She smokes meth regularly, takes tons of opiate pills and has already shot up heroin once. She has such a love for opioids that I am certain she'll do it again. I fear for her so much. She's out of state, and Swiv has no way to talk to her besides over the phone. Swiv found out today, and she is SO torn up over this. Swiv-sis even told their mom and Swiv-mom didn't do anything about it. Swiv-mom has just relapsed back into cancer and is apathetic to most everything now, it seems. Swiv hates to see this happening to her family. Is there anything Swiv can do, or is she doomed to watch her sister go down a path she's too young and too vulnerable to survive?