OK, 14.4 IS 15 hands,as there are only 4 inches to a hand, if the intended rider is 12 now, maybe a smaller horse would be even better. Size & weight mean more than age in today's measurements. How tall is the rider now, & how tall is she projected to be ? A lot of horses aren't done w/their youthful exburance even by the time they are 12, so my opinion is not to put an age limit on a good horse. I've known some 5 year-olds that were super calm, but that is the exception. There are lots of good horses but finding one that is available in a short time frame can sometimes be quite difficult. Keep an open mind & have someone very knowledgeable about horses & youngsters to help. Good luck!