Some get tipsy, some get sloppy. She was probably just tipsy. I remember back in HS. I was a sloppy drunk. Many of my friends were tipsy drunks. That carried over into adulthood. I don't drink now. Some of them had to quit too, some of them still drink responsibly.
If the report about her having spent the day snorkeling is true, I'm more inclined to think she was more than tipsy. But the thing about this case is that there is very little that we 'know' we know.