You are right there are so many unanswered question and the question to her would be what would getting answer as to why do to help that he stopped talking in this way told her he was going down stairs to get his phone charger and then left abruptly? How could he explain that away? If he was still talk about going to the wedding with her then things were pretty much still going well and something happened that changed his mind. If she really needs answer then she should call just to ease her mind from thinking it had anything to do with her but she may not get her answer even if she calls him and talks to him if he could be man enough to stay there and talk things through he may not be able to do so. I think in this case your daughter should not give him a second thought because he can just up and leave like that it's more than likely that he is used to treating women this way.
What your daughter should do is keep busy to take her mind off of the situation. Spend time with friends or find new hobbies to consume her time. She'll find that being able to distract herself can go a long way towards helping her feel better, so seize the opportunity to distract yourself and even to learn something new. She'll find that if she has recently experienced this type of treatment that she might not want to do anything at all. The problem with turning into a recluse because her feelings were hurt! She need to go to her brothers wedding and do some celebrating of her own celebrate that he showed his true colors before she got too deep in it. She should find someone like a friend who she trust and who will spend time listening to her so she can simply get everything off her chest. Unloading in this way can be instrumental for moving on, and she'll find that she can learn a great deal simply by making sure that she knows just what happened. Another plus here is that she'll be better able to avoid those same types of men in future relationships, and heed any warning signs she may have or rely on her intuition. When you have something to add click reply instead of opening another question box i's much easier and it's free.