Marijuana is illegal right now. That didn't stop that bad stuff from happening to you or your sister. Turn it into a public health issue and people like your sister-in-law will have more resources to get help.
I also have skepticism that marijuana caused someone to crash into your car. It has not been proven that weed has much if any effect on driving ability, especially for those experienced with the drug.
Marijuana is illegal right now. That didn't stop that bad stuff from happening to you or your sister. Turn it into a public health issue and people like your sister-in-law will have more resources to get help.
I also have skepticism that marijuana caused someone to crash into your car. It has not been proven that weed has much if any effect on driving ability, especially for those experienced with the drug.