What attitude about drinking are you talking about and why is it any of your business if she wants to have friends over and have alcohol? You aren't her mother.
What the heck is so alarming about having some friends over, eating, having some beer and playing cards? Are adults not allowed to do that? My goodness, it's not like they were doing keg stands and raving. The cops didn't get called because of some out of control party. She is a responsible adult, not some teenager at college.
This thread is not about her drinking habits, not that you could tell what those where from one evening in her life, it's about a horrible and tragic event. She has no control over what her friends do. I'm just glad that things did work out the way they did and that he ended up on her couch and not home alone where he would have aspirated on his own vomit and died.