As a mom this has to be difficult. The parents that talk in my alanon group really hit me the hardest I guess because I have 3 kids and I fear one day I will be dealing with what you have going on. I know my DS17 has been to parties and had beer and I try hard to put it into perspective. I went to parties at his age and had a few beers to and I turned out just fine, BUT his dad is an A, so I worry. Kids in college drink, and party but what is a normal amount? What as a parent should we be okay with? and if we aren't okay with it, then what? My first question to your daughter ,given what you just indicated, would be "how did you get home?" Drunk driving is very dangerous, period. As a parent I would struggle to know exactly how to handle this. Consequences yes, but what exactly? I'm sure others will be along with great advise for you. Alanon would be a great start if you aren't going.
Thank you for sharing. My heart really goes out to you. This is something I fear in my own life. I will be back to see what the experienced ones around here say.