This does not sound good at all. I agree that it seems odd she would go out alone, but that is coming from me, a socially awkward introvert. Are there any connections between this guy and ex? It doesn’t sound like it since the family seems to believe she didn’t know this guy. What I read it sounds like the guy picked her up but wasn’t in the bar/s? I may have read that wrong? If so, how did she communicate with him? Even Snapchat or What’s App and others, wouldn’t she need to have a starting point of communication before it moved to one of these texting apps (unless they met in person before). Also, what time was the flight the following day? If it was early morning then she needed at least three or four hours to pack and get to airport early enough for checking baggage, security, and boarding even if she wasn’t expecting to sleep that night. Also, she wouldn’t want to arrive at airport intoxicated. Too much thinking on that before even knowing if it was an early flight. I would also check dating apps. Maybe she used visiting her ex to explain why she was going but also planned on meeting someone else she had been talking to? I would check all the different dating apps to see if she was using any of them. Sending prayers for Marisela and family.