if anything i think they might be worse than Grand Mal's... only because if someone has a grand mal infront of you, you know know exactly what is going on. if someone has a petit mal, it might not get noticed. sorry if that scared you more...
Working out the trigger would be the first big thing, it might be something she can avoid. A friend at play group is fine with strobe lights etc.. but gets set off by the sunlight coming through the trees when she is a passenger in the car... so could be anything...
I hope your gp can help you out, keep us updated =)