how about don't tell the parents or call the cops and be a major SNITCH on your sister? that good enough for you people? or do you need to go out with a bang?
wait no, I have another solution. if it bugs you that much and you feel like you need to have so much control over her and her actions, talk to her about it.
or wait, you could let her figure it out on her own and stop using your parents ideology of "alcohol makes you evil" and "law above all" to help others.
"i care about my family therefore I will make their lives miserable to regret ever making poor choices. that way they will never end up homeless heroin junkies on the streets. they can thank me later"
"DRINKING A BIT OF WINE AT AN EARLY AGE? WHAT NEXT? MURDER?"
- a slippery snakes mindset