Anyone who's been through a bitter split after a long relationship will know one thing: it's hard to choose sides. There's friends of hers that you like and will never see again. Her brother kinda likes playing video games more with you than her. And let's not forget the fact that you met through a mutual friend, who now has to divide their time between the two of you.
Breaking up is hard - that's what we're basically saying. When a relationship melts down, your family and friends are caught in the crossfire. Often they have to take sides, or try and console both parties, or are simply witnesses to some uncomfortable secrets. No-one wants to involve the people you love into things like that, so if she's pulling away from them, it could be a hint that she's ready to split.