Let me start by saying that DD to took a little time to let things settle. Then, she tried again this morning by telling her friend that she thinks they should talk this out, in person, not texting, on a day and time good for both of them. Well, her BFF wanted no part of it and that was that. At first my daughter was hurt, but I started to tell her some of the good points in all of this. She soon realized that she was more relieved about breaking ties. She had been unhappy for months with how her BFF was treating her but tried being tolerant and understanding about the boyfriend entering her girlfriend's life. She tried being "available" for whenever it was convenient for her BFF and forgot about taking care of herself. She suddenly feels free to branch out and reconnect with some of the things she gave up doing.
As for the money I laid out for tickets and a few incidentals, the mom did call me today and owned up to paying me for those things. We had a good talk and hung up on good terms.
The good news: One of my daughter's favorite cousin's will now be joining us

! He can't stay the whole time because school starts for him on Aug 25th but we will be able to enjoy the first part of our vacation together. He will depart on Aug 24th. We head over to Universal on 26th and then home on the 29th. While at Universal, we will be meeting up with some long term friends!
Overall, a good ending to a very sad situation.
I want to thank you all for guiding me with your experience and advise. You guys ROCK!