Sorry to hear that.
At least she wasn't hurt or anything. Whenever I hear of people hitting animals with vehicles all I can think about is the time I hit a medium-sized black bear while riding my dad's Suzuki GS1100. Let's just say you don't forget something like that very easily...
After that, I'd rather take my chances in Chicago on a motorcycle as I've hit a bear and have had several very close encounters with deer. (Guess that's what happens when you're up in the middle of nowhere in WI...Actually working in the U.P. this summer since I'm so close.)
Mopar Fanatic said it best as there's always at least one deer on the side of the road at any given time.