You certainly don't act like 8th grade 
Aren't you 13? You're in no place to talk about his behavior.
If you read what you posted you would know that besides the potential for liver damage, which you aren't going to get unless you're drinking in excess regularly, there are no other confirmed health risks. And even the evidence they show there has only been done on animals, while animals studies can be good for neurological study, the only person who can benefit from the study of rats is OP.
Well it's not like they have much opportunity to study. Obviously they can't hold a trial where they give kids alcohol, so the only data they have is of kids who they know drank at one point, they can't isolate the "drank while developing" variable.
find his parents on fb and tell them about his research XD
you can be really childish
10/10 gave me a chuckle.
You're working entirely in black and white. Your argument operates on the assumption that all underage drinkers would need to be stupid, all stupid people would forever be stupid.
That being said, calling the cops is too far. There's no point in having anything put on her record. Tell your parents.