If this behavior is not typical for her, you need to consider the possibility that a drink may have been spiked, which does happen at work conference after parties. A coworker of mine called me from her hotel in a similar state to your GF. She called me sobbing after her husband chewed her out for calling him drunk. In 10 yrs of knowing her & conferences, I’d never seen her tipsy or have more than 2 drinks. Something felt off. I went to her room & had she been a regular partier I’d have assumed she was sloshed. But I knew the was atypical & another coworker and I ubered her to the nearby urgent care. Her blood alcohol level was low, but she tested positive for the date rape drug. Her rape kit was negative thankfully & they suspect she didn’t drink very much of the spiked drink so she was able to get back to her room. Until talking to the doctor, the jerky husband was convinced that she’d partied it up & had an affair at the conference. The police said it happens more often than you think at conferences, but in her case no one was ever caught