The entire extended family and us are buying each of my girls an ATV.
A bit crazy but both of our girls currently drive my Polaris 700 which is NOT safe as if they rolled it, they would most likely not survive. I need mine for plowing snow, hauling hay/feed and so forth, so trading it in for a smaller ATV isn't an option.
The girls have proven that they safely stay at 5mph or less on mine and have only had the keys confiscated for fighting over it, not unsafe or stupid use of it.
So helmets and ATV's it is. They are getting 125cc ones that have racks (since I DO expect them to haul feed/water out to their animals) and speed control (act like a maniac and they'll find it only goes 2mph! HAHA).
DH already built them a dirt track (they think it's for me and my ATV) so this should be fun. If nothing else, I am thrilled that I will no longer go outside to feed pigs and see MINE 80 billion miles away because the kids went for a joy ride!