What should I do to help my friend who is an alcoholic? We are only in 8th grade!?

We watched a video together about what drinking can do to hurt you and that you shouldn't do it but she just ignored it and said she didn't really care about they said!!! all you fellow people out there i really would like to hear you alls advice and help on what I should do?! Should I just let her keep on drinking I'm scared for her?