perhaps I am speaking form my experience alone, my sibling girls always get along better then a few different girls. but that could also be because they have been raised together and have the hierarchy all worked out from the beginning. modaz is right though, they always could choose to pick fights with each other. I always had a spare something to put a girl in if the others decided to gang up on her. my girls now all live divided, because the little ones would pick one large out and gang up on her.