Milestones, Smilestones

Tonight dd2 had fun jumping around for a while. At one point, she two-foot-jumped six times in a row before her movement became a run-gallop. According to this PBS website, that's a developmental milestone typically reached by a 4 to 5 year old child. Should I sign dd2 up for sports lessons right now?? Just kidding. "Developmental milestones" shouldn't cause a parent to damage a toddler's love of movement. Besides, what coach will take on a child who hasn't given up diapers yet?