Well, when I resurrected the Tricous (the dead family that came with Nightlife) the teen girl beat the snot out of her aunt. I did have the inteenimater installed at the time though so it could have been the reason the aunt was able to attack her niece--and yes she started the cat fight.
But just recently I again resurrected the same family in my Pleasantview hood (this time without having inteenimater installed) and the aunt and the teen girl had minus relationship points for each other so something must have happened before they died. They didn't attack each other in this resurrection because I made damned sure to seperate the families immediatly upon resurrection. I just didn't want to take a chance.
I have enough Sims disrupting each other lives, by stealing newspapers and giving each other the flue via the trashcan