Your daughter and her friend are 19 years old???? what is the legal drinking age in your state. In my state, NJ parents who allow underage drinking are held liable and charged.
you have to think of the legal ramifications too....she's walking the streets without pants on and gets picked up, YOU are going to have to answer for it and pay the hefty fines.
I think that you are going to have to be very firm about what is acceptable behavior and stop pussyfooting around...WHY did you not wake up your husband for support?
These photos of nudity and drunken behavior on facebook will be following her around in 10 years (if she lasts that long)....If she's not embarrassed for herself, it's up to you to step in as her PARENT. why didn't you call her friend's parents and ask them to pick up their own drunk kid? they are running your life???
I don't mean to sound harsh, but if you don't put your foot down, it will escalate....your $$$, your house, your rules....let her take some responsibility or next year at school will be a repeat performance.