I never thought I'd do this, but I agree with Cool-Beans. Road rage is road rage. A cup filled with ice is what she had at hand, but what if it had been something not nearly so innocuous? What if it had hit the other driver just right, and caused her to lose control of her car? She lost control of herself, WHILE she was behind the wheel of a car, and WHILE she had small children in the car. Not that has anything to do with the charge, but if she acted with such disregard in a position of such responsibility, she cared not for the repercussions of her actions, and needs a little legal punishment to teach her.
Two years seems like a lot, yeah, and I wish that judges had more leeway with extenuating circumstances, but she definitely deserves something more than a slap on the wrist.