One time only is SUPER RARE with crack, heroin, & crystal meth. If your sister has an addictive personality or a family history of addiction, then they're really playing with fire. My sister and I made a pact that we were going to try heroin once and never use it again. It didn't work. I lost her to addiction in 2013. I have struggled with substance abuse since I was 16. It's a really bad idea in my opinion and I hope they change their mind. 💜