Is that the first time you've had a whole houseful? It might have just been a little too much stimulation for Keisha. Does she usually get along with your MIL's dog? Sounds like she was just like a pre-schooler who just has too many people around - HYPER. Is she pretty well disciplined otherwise?
And isn't it funny.... they either sense those that aren't dog people and ignore them OR try to convert them to dog people like smothering them with dog loving/playing!!