I live in the U.S. where the drinking age is 21. When I was 16 i started drinking occasionally and i made sure I told my mom. She definately had a problem with it but telling her made our relationship more open and she could trust me more. it was known that i wasn't allowed to but as a teenager it's expected and as much as we would like to believe it our children don't follow all of our rules. Just make sure she knows it is against the rules...but she can tell you about it. My mom always made sure i knew that if I was somewhere where there was drinking and I felt uncomfrtable she would come pick me up. The best you can do is tell her whats right and wrong and trust her enough to know she'll make the right choice. If she comes to you and says she was out somewhere where there was drinking don't go ballsitic on her. that will ruin the open trust relationship.