There are at least two reasons she could have used messenger to try and contact her friends. One, she doesn’t know her friends phone numbers by heart or two, she is accustomed to using messenger through wifi because she normally has a phone but doesn’t have an active phone plan to call and text. If the boyfriend got home the same day, that means he checked out of the hotel and left very early in the morning. It’s a long day of driving to get from Vegas to Washington. Who were the other friends who stuck around for some time looking for her? They have to know more than has been published so far.