Interesting. I honestly think it's the glutamine. She is skinny and looks like she has a fast metabolism. And she doesn't have to be out partying, she can just drink at home or whatever and same effect, so it's definitely not the sugar or caffeine.
I found this strange because personally I sleep pretty well after alcohol. If I drink a glass of wine or a beer or two before bed I pass out like a rock and feel super refreshed the next day.
Although if I drink heavily, it's a 50/50, I could be passed out all day, or I could wake up super early.